[IA64] disable interrupts when exiting from ia64_mca_cmc_int_handler()

SAL specification mandates that ia64_mca_log_sal_error_record() gets
called with interrupts enabled, and that's why ia64_mca_cmc_int_handler()
is enabling them. It however forgets to re-disable them when exiting,
which triggers WARN_ON() in generic IRQ handler.

Disable the interrupts again before exiting. This is analogous to
a3967685 ("[IA64] disable interrupts at end of ia64_mca_cpe_int_handler()").

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Tony Luck <tony.luck@intel.com>