posix-cpu-timers: Remove lockdep_assert_irqs_disabled()

The lockdep_assert_irqs_disabled() was a BUG_ON() statement in the
beginning and it was added just before the "spin_lock(siglock)"
statement to ensure this lock was taken with disabled interrupts.

This is no longer the case: the siglock is acquired via
lock_task_sighand() and this function already disables the interrupts.
The lock is also acquired before this "lockdep_assert_irqs_disabled" so
it is best to remove it.

Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Link: https://lkml.kernel.org/[e-mail]

kernel/time/posix-cpu-timers.c

···
 	/*
 	 * Disarm any old timer after extracting its expiry time.
 	 */
-	lockdep_assert_irqs_disabled();
 
 	ret = 0;
 	old_incr = timer->it.cpu.incr;
···
 	/*
 	 * Now re-arm for the new expiry time.
 	 */
-	lockdep_assert_irqs_disabled();
 	arm_timer(timer);
 unlock:
 	unlock_task_sighand(p, &flags);