x86: more users of PF_ constants in fault_32|64.c

Should be the last of the error_code tests that could use
the PF_ defines.  Makes X86_32|64 a little closer.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c
index 058b04c..95f142f 100644
--- a/arch/x86/mm/fault_64.c
+++ b/arch/x86/mm/fault_64.c
@@ -677,7 +677,7 @@
 		goto again;
 	}
 	printk("VM: killing process %s\n", tsk->comm);
-	if (error_code & 4)
+	if (error_code & PF_USER)
 		do_group_exit(SIGKILL);
 	goto no_context;