fs: nfsd: fileache.c: Use built-in RCU list checking

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when  CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/filecache.c

@@ -890,7 +890,7 @@ nfsd_file_find_locked(struct inode *inode, unsigned int may_flags,
 	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
 
 	hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head,
-				 nf_node) {
+				 nf_node, lockdep_is_held(&nfsd_file_hashtbl[hashval].nfb_lock)) {
 		if ((need & nf->nf_may) != need)
 			continue;
 		if (nf->nf_inode != inode)