[IA64] disable interrupts at end of ia64_mca_cpe_int_handler()

SAL requires that interrupts be enabled when making some calls
to it to pick up error records, so we enable interrupts inside
this handler.  We should disable them again at the end.

Found by a new WARN_ONCE that tglx added to handle_irq_event_percpu()
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/mca.c

@@ -582,6 +582,8 @@ ia64_mca_cpe_int_handler (int cpe_irq, void *arg)
 	/* Get the CPE error record and log it */
 	ia64_mca_log_sal_error_record(SAL_INFO_TYPE_CPE);
 
+	local_irq_disable();
+
 	return IRQ_HANDLED;
 }