Deprecate ErrNoGoFiles as it's never returned

Author: alexandear

Diff for: errcheck/errcheck.go

@@ -23,7 +23,9 @@ func init() {
 }
 
 var (
-	// ErrNoGoFiles is returned when CheckPackage is run on a package with no Go source files
+	// ErrNoGoFiles is returned when CheckPackage is run on a package with no Go source files.
+	//
+	// Deprecated: this error is no longer returned by errcheck.LoadPackages.
 	ErrNoGoFiles = errors.New("package contains no go source files")
 )
 

Diff for: main.go

@@ -121,10 +121,6 @@ func mainCmd(args []string) int {
 
 	result, err := checkPaths(&checker, paths...)
 	if err != nil {
-		if err == errcheck.ErrNoGoFiles {
-			fmt.Fprintln(os.Stderr, err)
-			return exitCodeOk
-		}
 		fmt.Fprintf(os.Stderr, "error: failed to check packages: %s\n", err)
 		return exitFatalError
 	}