i965: Remove brw_set_predicate_inverse(p, true) from scratch offset code

i965: Remove brw_set_predicate_inverse(p, true) from scratch offset code

Given that it exists between a push/pop of instruction state, this call
can only affect the MOV or ADD instruction generated just below it.
Neither of those instructions are predicated, so it makes no sense to
ask for the inverse predicate.

This fixes grumblings from the simulator debugger, which was
complaining about an invalid predicate.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>