fs: take the ACL checks to common code

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 5f243cd..9659b7c 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -56,7 +56,7 @@
 	.rmdir =	jffs2_rmdir,
 	.mknod =	jffs2_mknod,
 	.rename =	jffs2_rename,
-	.check_acl =	jffs2_check_acl,
+	.get_acl =	jffs2_get_acl,
 	.setattr =	jffs2_setattr,
 	.setxattr =	jffs2_setxattr,
 	.getxattr =	jffs2_getxattr,