Fix the Linux build with clang.

Review URL: https://breakpad.appspot.com/470002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1052 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/linux/handler/exception_handler_unittest.cc

@@ -222,6 +222,7 @@ static bool DoneCallbackRaiseSIGKILL(const MinidumpDescriptor& descriptor,
                                      void* context,
                                      bool succeeded) {
   raise(SIGKILL);
+  return true;
 }
 
 static bool FilterCallbackReturnFalse(void* context) {