x86: apic - calibrate_APIC_clock remove redundant irq-enable-disable

Impact: cleanup

lapic_timer_setup is self-protected with local_irq_save/restore
no need to use them in caller and levt is the per-cpu variable so
no concurrent access from another cpu.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic.c

@@ -672,13 +672,9 @@ static int __init calibrate_APIC_clock(void)
 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
 			cpu_relax();
 
-		local_irq_disable();
-
 		/* Stop the lapic timer */
 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
 
-		local_irq_enable();
-
 		/* Jiffies delta */
 		deltaj = lapic_cal_j2 - lapic_cal_j1;
 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);