Fix `go vet` issues

Test: go vet ./...
Change-Id: Ifb936ccc5e2b5a2c3fcbbbcb54f680e2973ea1b3
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.