s390: fix comment regarding interrupts in svc

With the removal of the critical section cleanup, we now enter the svc
interrupt handler with interrupts disabled.

Fixes: 0b0ed657 ("s390: remove critical section cleanup from entry.S")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/kernel/entry.S

@@ -370,7 +370,7 @@ EXPORT_SYMBOL(sie_exit)
 
 /*
  * SVC interrupt handler routine. System calls are synchronous events and
- * are executed with interrupts enabled.
+ * are entered with interrupts disabled.
  */
 
 ENTRY(system_call)