setup vma->vm_page_prot by vm_get_page_prot()

This patch uses vm_get_page_prot() to setup vma->vm_page_prot.

Though inside vm_get_page_prot() the protection flags is AND with
(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED), it does not hurt correct code.

Signed-off-by: Coly Li <coyli@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/exec.c b/fs/exec.c
index 070ddf13..0b09447 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -234,7 +234,7 @@
 	vma->vm_start = vma->vm_end - PAGE_SIZE;
 
 	vma->vm_flags = VM_STACK_FLAGS;
-	vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
+	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 	err = insert_vm_struct(mm, vma);
 	if (err) {
 		up_write(&mm->mmap_sem);