signal/x86: Don't compute pkey in __do_page_fault

There are no more users of the computed pkey value in __do_page_fault
so stop computing the value.
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

arch/x86/mm/fault.c

@@ -1216,7 +1216,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	struct mm_struct *mm;
 	vm_fault_t fault, major = 0;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
-	u32 pkey;
 
 	tsk = current;
 	mm = tsk->mm;
@@ -1388,10 +1387,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	 * (potentially after handling any pending signal during the return to
 	 * userland). The return to userland is identified whenever
 	 * FAULT_FLAG_USER|FAULT_FLAG_KILLABLE are both set in flags.
-	 * Thus we have to be careful about not touching vma after handling the
-	 * fault, so we read the pkey beforehand.
 	 */
-	pkey = vma_pkey(vma);
 	fault = handle_mm_fault(vma, address, flags);
 	major |= fault & VM_FAULT_MAJOR;