perf/x86: Fix PEBS instruction unwind

perf/x86: Fix PEBS instruction unwind

commit 57d1c0c03c6b48b2b96870d831b9ce6b917f53ac upstream.

Masami spotted that we always try to decode the instruction stream as
64bit instructions when running a 64bit kernel, this doesn't work for
ia32-compat proglets.

Use TIF_IA32 to detect if we need to use the 32bit instruction
decoder.

Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>