Removed unused return variables.

Sometimes it is confused that these variables are mixed with ninja
parameters when invoking pctx.AndroidStaticRule()/SourcePathVariable().

Test: m -j
Change-Id: Ibcf17eeed6ac79aafaa5edeec27427721b36e75a
diff --git a/cc/builder.go b/cc/builder.go
index f3a4bcb..cdfea92 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -109,7 +109,7 @@
 		},
 		"objcopyCmd", "prefix")
 
-	stripPath = pctx.SourcePathVariable("stripPath", "build/soong/scripts/strip.sh")
+	_ = pctx.SourcePathVariable("stripPath", "build/soong/scripts/strip.sh")
 
 	strip = pctx.AndroidStaticRule("strip",
 		blueprint.RuleParams{
@@ -127,7 +127,7 @@
 			Description: "empty file $out",
 		})
 
-	copyGccLibPath = pctx.SourcePathVariable("copyGccLibPath", "build/soong/scripts/copygcclib.sh")
+	_ = pctx.SourcePathVariable("copyGccLibPath", "build/soong/scripts/copygcclib.sh")
 
 	copyGccLib = pctx.AndroidStaticRule("copyGccLib",
 		blueprint.RuleParams{
@@ -139,7 +139,7 @@
 		},
 		"ccCmd", "cFlags", "libName")
 
-	tocPath = pctx.SourcePathVariable("tocPath", "build/soong/scripts/toc.sh")
+	_ = pctx.SourcePathVariable("tocPath", "build/soong/scripts/toc.sh")
 
 	toc = pctx.AndroidStaticRule("toc",
 		blueprint.RuleParams{
@@ -159,7 +159,7 @@
 		},
 		"cFlags", "tidyFlags")
 
-	yasmCmd = pctx.SourcePathVariable("yasmCmd", "prebuilts/misc/${config.HostPrebuiltTag}/yasm/yasm")
+	_ = pctx.SourcePathVariable("yasmCmd", "prebuilts/misc/${config.HostPrebuiltTag}/yasm/yasm")
 
 	yasm = pctx.AndroidStaticRule("yasm",
 		blueprint.RuleParams{