x86, compat: Use test_thread_flag(TIF_IA32) in compat signal delivery

commit 0b91f45b23cb73ce11acdc3cf4c6efd4441e3b3e upstream.

Signal delivery compat path may not have the 'TS_COMPAT' flag (that
flag indicates how we entered the kernel).  So use
test_thread_flag(TIF_IA32) instead of is_ia32_task(): one of the
functions of TIF_IA32 is just what kind of signal frame we want.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1339722435.3475.57.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>