vfs: renumber DCACHE_xyz flags, remove some stale ones

Gcc tends to generate better code with small integers, including the
DCACHE_xyz flag tests - so move the common ones to be first in the list.
Also just remove the unused DCACHE_INOTIFY_PARENT_WATCHED and
DCACHE_AUTOFS_PENDING values, their users no longer exists in the source
tree.

And add a "unlikely()" to the DCACHE_OP_COMPARE test, since we want the
common case to be a nice straight-line fall-through.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dcache.c b/fs/dcache.c
index c83cae1..a88948b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1729,7 +1729,7 @@
 		 */
 		if (read_seqcount_retry(&dentry->d_seq, *seq))
 			goto seqretry;
-		if (parent->d_flags & DCACHE_OP_COMPARE) {
+		if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {
 			if (parent->d_op->d_compare(parent, *inode,
 						dentry, i,
 						tlen, tname, name))