Fix `go vet` issues

Test: go vet ./...
Change-Id: Ifb936ccc5e2b5a2c3fcbbbcb54f680e2973ea1b3
diff --git a/cc/cc.go b/cc/cc.go
index 89d45a9..f8a8225 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -991,33 +991,41 @@
 		actx.AddVariationDependencies(nil, depTag, lib)
 	}
 
-	actx.AddVariationDependencies([]blueprint.Variation{{"link", "static"}}, wholeStaticDepTag,
-		deps.WholeStaticLibs...)
+	actx.AddVariationDependencies([]blueprint.Variation{
+		{Mutator: "link", Variation: "static"},
+	}, wholeStaticDepTag, deps.WholeStaticLibs...)
 
 	for _, lib := range deps.StaticLibs {
 		depTag := staticDepTag
 		if inList(lib, deps.ReexportStaticLibHeaders) {
 			depTag = staticExportDepTag
 		}
-		actx.AddVariationDependencies([]blueprint.Variation{{"link", "static"}}, depTag, lib)
+		actx.AddVariationDependencies([]blueprint.Variation{
+			{Mutator: "link", Variation: "static"},
+		}, depTag, lib)
 	}
 
-	actx.AddVariationDependencies([]blueprint.Variation{{"link", "static"}}, lateStaticDepTag,
-		deps.LateStaticLibs...)
+	actx.AddVariationDependencies([]blueprint.Variation{
+		{Mutator: "link", Variation: "static"},
+	}, lateStaticDepTag, deps.LateStaticLibs...)
 
 	for _, lib := range deps.SharedLibs {
 		depTag := sharedDepTag
 		if inList(lib, deps.ReexportSharedLibHeaders) {
 			depTag = sharedExportDepTag
 		}
-		actx.AddVariationDependencies([]blueprint.Variation{{"link", "shared"}}, depTag, lib)
+		actx.AddVariationDependencies([]blueprint.Variation{
+			{Mutator: "link", Variation: "shared"},
+		}, depTag, lib)
 	}
 
-	actx.AddVariationDependencies([]blueprint.Variation{{"link", "shared"}}, lateSharedDepTag,
-		deps.LateSharedLibs...)
+	actx.AddVariationDependencies([]blueprint.Variation{
+		{Mutator: "link", Variation: "shared"},
+	}, lateSharedDepTag, deps.LateSharedLibs...)
 
-	actx.AddVariationDependencies([]blueprint.Variation{{"link", "shared"}}, runtimeDepTag,
-		deps.RuntimeLibs...)
+	actx.AddVariationDependencies([]blueprint.Variation{
+		{Mutator: "link", Variation: "shared"},
+	}, runtimeDepTag, deps.RuntimeLibs...)
 
 	actx.AddDependency(c, genSourceDepTag, deps.GeneratedSources...)
 
@@ -1043,9 +1051,13 @@
 
 	version := ctx.sdkVersion()
 	actx.AddVariationDependencies([]blueprint.Variation{
-		{"ndk_api", version}, {"link", "shared"}}, ndkStubDepTag, variantNdkLibs...)
+		{Mutator: "ndk_api", Variation: version},
+		{Mutator: "link", Variation: "shared"},
+	}, ndkStubDepTag, variantNdkLibs...)
 	actx.AddVariationDependencies([]blueprint.Variation{
-		{"ndk_api", version}, {"link", "shared"}}, ndkLateStubDepTag, variantLateNdkLibs...)
+		{Mutator: "ndk_api", Variation: version},
+		{Mutator: "link", Variation: "shared"},
+	}, ndkLateStubDepTag, variantLateNdkLibs...)
 
 	if vndkdep := c.vndkdep; vndkdep != nil {
 		if vndkdep.isVndkExt() {
@@ -1054,8 +1066,9 @@
 				baseModuleMode = coreMode
 			}
 			actx.AddVariationDependencies([]blueprint.Variation{
-				{"image", baseModuleMode}, {"link", "shared"}}, vndkExtDepTag,
-				vndkdep.getVndkExtendsModuleName())
+				{Mutator: "image", Variation: baseModuleMode},
+				{Mutator: "link", Variation: "shared"},
+			}, vndkExtDepTag, vndkdep.getVndkExtendsModuleName())
 		}
 	}
 }
diff --git a/cc/compiler.go b/cc/compiler.go
index 8d034c9..f3cf040 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -73,7 +73,7 @@
 
 	// list of directories relative to the Blueprints file that will
 	// be added to the include path using -I
-	Local_include_dirs []string `android:"arch_variant,variant_prepend",`
+	Local_include_dirs []string `android:"arch_variant,variant_prepend"`
 
 	// list of generated sources to compile. These are the names of gensrcs or
 	// genrule modules.
diff --git a/cc/config/toolchain.go b/cc/config/toolchain.go
index ea8397d..a360a17 100644
--- a/cc/config/toolchain.go
+++ b/cc/config/toolchain.go
@@ -36,7 +36,6 @@
 	factory := toolchainFactories[os][arch.ArchType]
 	if factory == nil {
 		panic(fmt.Errorf("Toolchain not found for %s arch %q", os.String(), arch.String()))
-		return nil
 	}
 	return factory(arch)
 }
diff --git a/cc/test_data_test.go b/cc/test_data_test.go
index 56c3e38..eead25b 100644
--- a/cc/test_data_test.go
+++ b/cc/test_data_test.go
@@ -15,7 +15,6 @@
 package cc
 
 import (
-	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -154,7 +153,7 @@
 				path := filepath.Join(test.data[i].path, test.data[i].file)
 				if test.data[i].file != got[i].Rel() ||
 					path != got[i].String() {
-					fmt.Errorf("expected %s:%s got %s:%s",
+					t.Errorf("expected %s:%s got %s:%s",
 						path, test.data[i].file,
 						got[i].String(), got[i].Rel())
 				}