bison: fix glr parser on 32-bit builds.

Bison has switched 'yyk' variables to be ptrdiff_t instead of size_t and
is printing them with %ld. We could switch this to %td, but in order to
be consistent with the rest of this template, adding a cast.

Bug: 31194194
Test: builds

Change-Id: Ia328093604d590b557b27e648967b563b059183e
1 file changed