yasm: Fix a compile error introduced by my last commit.

(Upstream at https://github.com/yasm/yasm/pull/63)

TBR=fischman
Review URL: https://chromiumcodereview.appspot.com/9669043

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/yasm/patched-yasm@126079 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
1 file changed