nfsd: use a long for the count in nfsd4_state_shrinker_count()

If there are no courtesy clients then the return value from the
atomic_long_read() could overflow an int. Use a long to store the value
instead.

Signed-off-by: Jeff Layton <[e-mail]>
Signed-off-by: Chuck Lever <[e-mail]>

fs/nfsd/nfs4state.c

···
 static unsigned long
 nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
 {
-	int count;
 	struct nfsd_net *nn = shrink->private_data;
+	long count;
 
 	count = atomic_read(&nn->nfsd_courtesy_clients);
 	if (!count)