sunrpc/cache: fix module refcnt leak in a failure path

sunrpc/cache: fix module refcnt leak in a failure path

commit a5990ea1254cd186b38744507aeec3136a0c1c95 upstream

Don't forget to release the module refcnt if seq_open() returns failure.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>