clang-format: Fix corner-case in ObjC method declaration formatting

Before:
  - (void)shortf:(GTMFoo *)theFoo
     longKeyword:(NSRect)theRect
   longerKeyword:(float)theInterval
           error:(NSError **)theError {
  }

After:
  - (void)shortf:(GTMFoo *)theFoo
        longKeyword:(NSRect)theRect
      longerKeyword:(float)theInterval
              error:(NSError **)theError {
  }

llvm-svn: 256738