ARM: pgtable: invert L_PTE_EXEC to L_PTE_XN

The hardware page tables use an XN bit 'execute never'.  Historically,
we've had a Linux 'execute allow' bit, in the positive sense.  Get rid
of this artifact as future hardware will continue to have the XN sense.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 89c31a6..4f5a594 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -149,8 +149,8 @@
 	tstne	r3, #PTE_EXT_APX
 	bicne	r3, r3, #PTE_EXT_APX | PTE_EXT_AP0
 
-	tst	r1, #L_PTE_EXEC
-	orreq	r3, r3, #PTE_EXT_XN
+	tst	r1, #L_PTE_XN
+	orrne	r3, r3, #PTE_EXT_XN
 
 	tst	r1, #L_PTE_YOUNG
 	tstne	r1, #L_PTE_PRESENT