Fix LexerTest signed/unsigned comparison.

Werror was catching a signed/unsigned compare in 
an assert, correct the signed 'expected' value to be
unsigned.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@305435 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Lex/LexerTest.cpp

@@ -383,7 +383,7 @@ TEST_F(LexerTest, DontOverallocateStringifyArgs) {
   MacroInfo *MI = PP->AllocateMacroInfo({});
   MI->setIsFunctionLike();
   MI->setArgumentList(ArgList, Allocator);
-  EXPECT_EQ(3, MI->getNumArgs());
+  EXPECT_EQ(3u, MI->getNumArgs());
   EXPECT_TRUE(MI->isFunctionLike());
 
   Token Eof;