Simplified if construct

Author: cmaglie

legacy/builder/container_find_includes.go

@@ -364,14 +364,11 @@ func findIncludesUntilDone(ctx *types.Context, cache *includeCache, sourceFile *
 		} else {
 			preproc_stderr, preproc_err = GCCPreprocRunnerForDiscoveringIncludes(ctx, sourcePath, targetFilePath, includes)
 			// Unwrap error and see if it is an ExitError.
-			_, is_exit_error := errors.Cause(preproc_err).(*exec.ExitError)
 			if preproc_err == nil {
 				// Preprocessor successful, done
 				include = ""
-			} else if !is_exit_error || preproc_stderr == nil {
-				// Ignore ExitErrors (e.g. gcc returning
-				// non-zero status), but bail out on
-				// other errors
+			} else if _, isExitErr := errors.Cause(preproc_err).(*exec.ExitError); !isExitErr || preproc_stderr == nil {
+				// Ignore ExitErrors (e.g. gcc returning non-zero status), but bail out on other errors
 				return errors.WithStack(preproc_err)
 			} else {
 				include = IncludesFinderWithRegExp(string(preproc_stderr))