Return 1 in main() to stop the build system when there's an error.

Change-Id: Ibc75155278e1d2dd820a000baabeaac0d651badc
diff --git a/llvm-rs-cc.cpp b/llvm-rs-cc.cpp
index 37987d6..03fdd45 100644
--- a/llvm-rs-cc.cpp
+++ b/llvm-rs-cc.cpp
@@ -432,9 +432,8 @@
                             OutputFile,
                             DepOutputFile,
                             Opts)) {
-      llvm::errs() << "Failed to compile '" << InputFile << "' ("
-                   << Compiler->getErrorMessage() << ")";
-      break;
+      llvm::errs() << Compiler->getErrorMessage();
+      return 1;
     }
   }