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/jfs/namei.c b/fs/jfs/namei.c
index 03787ef..29b1f1a 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1537,7 +1537,7 @@
 	.removexattr	= jfs_removexattr,
 	.setattr	= jfs_setattr,
 #ifdef CONFIG_JFS_POSIX_ACL
-	.check_acl	= jfs_check_acl,
+	.get_acl	= jfs_get_acl,
 #endif
 };