arm64: entry: Remove unneeded need_resched() loop

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.
Reported-by: Julien Thierry <julien.thierry@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/entry.S

@@ -611,7 +611,7 @@ el1_irq:
 #ifdef CONFIG_PREEMPT
 	ldr	x24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
 	cbnz	x24, 1f				// preempt count != 0
-	bl	el1_preempt
+	bl	preempt_schedule_irq		// irq en/disable is done inside
 1:
 #endif
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -620,15 +620,6 @@ el1_irq:
 	kernel_exit 1
 ENDPROC(el1_irq)
 
-#ifdef CONFIG_PREEMPT
-el1_preempt:
-	mov	x24, lr
-1:	bl	preempt_schedule_irq		// irq en/disable is done inside
-	ldr	x0, [tsk, #TSK_TI_FLAGS]	// get new tasks TI_FLAGS
-	tbnz	x0, #TIF_NEED_RESCHED, 1b	// needs rescheduling?
-	ret	x24
-#endif
-
 /*
  * EL0 mode handlers.
  */