Revert "install *.so in different paths for their types"

This reverts commit 4c48f724e1b339128447ab1dafd656a9557557f5. It's
causing test failures, warnings and complaints, so backing it out and
we'll resolve those before putting it back in.

Bug: 33681361
Test: m -j
diff --git a/cc/installer.go b/cc/installer.go
index de04ab6..64f87d9 100644
--- a/cc/installer.go
+++ b/cc/installer.go
@@ -47,7 +47,6 @@
 
 	dir      string
 	dir64    string
-	subDir   string
 	relative string
 	location installLocation
 
@@ -61,14 +60,14 @@
 }
 
 func (installer *baseInstaller) installDir(ctx ModuleContext) android.OutputPath {
-	dir := installer.dir
+	subDir := installer.dir
 	if ctx.toolchain().Is64Bit() && installer.dir64 != "" {
-		dir = installer.dir64
+		subDir = installer.dir64
 	}
 	if !ctx.Host() && !ctx.Arch().Native {
-		dir = filepath.Join(dir, ctx.Arch().ArchType.String())
+		subDir = filepath.Join(subDir, ctx.Arch().ArchType.String())
 	}
-	return android.PathForModuleInstall(ctx, dir, installer.subDir, installer.Properties.Relative_install_path, installer.relative)
+	return android.PathForModuleInstall(ctx, subDir, installer.Properties.Relative_install_path, installer.relative)
 }
 
 func (installer *baseInstaller) install(ctx ModuleContext, file android.Path) {