nfsd: ensure that st_access_bmap and st_deny_bmap are initialized to 0

Open stateids must be initialized with the st_access_bmap and
st_deny_bmap set to 0, so that nfs4_get_vfs_file can properly record
their state in old_access_bmap and old_deny_bmap.

This bug was introduced in commit baeb4ff (nfsd: make deny mode
enforcement more efficient and close races in it) and was causing the
refcounts to end up incorrect when nfs4_get_vfs_file returned an error
after bumping the refcounts. This made it impossible to unmount the
underlying filesystem after running pynfs tests that involve deny modes.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -2970,8 +2970,6 @@ static void init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp,
 	stp->st_file = fp;
 	stp->st_access_bmap = 0;
 	stp->st_deny_bmap = 0;
-	set_access(open->op_share_access, stp);
-	set_deny(open->op_share_deny, stp);
 	stp->st_openstp = NULL;
 	spin_lock(&fp->fi_lock);
 	list_add(&stp->st_perfile, &fp->fi_stateids);