asmlinkage: Make trace_hardirqs_on/off_caller visible

These functions are called from assembler, and thus need to be
__visible.

Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391845930-28580-12-git-send-email-ak@linux.intel.com


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>