NFS/pNFS: Fix a leak of the layout 'plh_outstanding' counter

stable inclusion
from stable-5.10.9
commit 01a12a24f9238024f69ee0b15ffa73511ba6c95f
bugzilla: 47457

--------------------------------

commit cb2856c5 upstream.

If we exit _lgopen_prepare_attached() without setting a layout, we will
currently leak the plh_outstanding counter.

Fixes: 411ae722 ("pNFS: Wait for stale layoutget calls to complete in pnfs_update_layout()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>