[ARM] Fix kernel mode preemption

Luc Van Oostenryck reported:

  The code removed by this patch tested the irq_cpustat_t members
  __local_irq_count and __local_bh_count but these fields have
  been removed some time ago:

  http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=3ab146c93e039dec99fec8d441a8dd046fe510cc



Fix this oversight.

Acked-by: Bill Gatliff <bgat@billgatliff.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>