Fix integer formatting compiler warning when building for 64 bit architecture.
The reason is NSInteger is defined as long for 64bit.

DELTA=1  (0 added, 0 deleted, 1 changed)

git-svn-id: http://google-toolbox-for-mac.googlecode.com/svn/trunk@656 7dc7ac4e-7543-0410-b95c-c1676fc8e2a3