x86: fix warning

&ptep->pte isn't always an unsigned long *, so cast it to avoid a warning.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
index 62fa856..820db41 100644
--- a/include/asm-x86/pgtable.h
+++ b/include/asm-x86/pgtable.h
@@ -275,7 +275,7 @@
 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
-	clear_bit(_PAGE_BIT_RW, &ptep->pte);
+	clear_bit(_PAGE_BIT_RW, (unsigned long *)&ptep->pte);
 	pte_update(mm, addr, ptep);
 }