Document on exit code in case of MultiError is given

errors.go

@@ -74,7 +74,7 @@ func (ee *ExitError) ExitCode() int {
 // HandleExitCoder checks if the error fulfills the ExitCoder interface, and if
 // so prints the error to stderr (if it is non-empty) and calls OsExiter with the
 // given exit code.  If the given error is a MultiError, then this func is
-// called on all members of the Errors slice.
+// called on all members of the Errors slice and calls OsExiter with the last exit code.
 func HandleExitCoder(err error) {
 	if err == nil {
 		return