internal/rosa/cmake: remove variant

This has no effect outside formatting of name and is a remnant of the old llvm helpers.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/musl.go

@@ -62,7 +62,7 @@ rmdir -v /work/lib
 func init() {
 	artifactsM[Musl] = Metadata{
 		f: func(t Toolchain) (pkg.Artifact, string) {
-			return t.newMusl(false, t.Load(LLVMCompilerRT))
+			return t.newMusl(false, t.Load(CompilerRT))
 		},
 
 		Name:        "musl",