NFSv4: add declaration of current_stateid

The current_stateid is exported from nfs4state.c but not
declared in any of the headers. Add to nfs4_fs.h to
remove the following warning:

fs/nfs/nfs4state.c:80:20: warning: symbol 'current_stateid' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs4_fs.h

@@ -454,6 +454,8 @@ extern void nfs4_set_lease_period(struct nfs_client *clp,
 
 
 /* nfs4state.c */
+extern const nfs4_stateid current_stateid;
+
 const struct cred *nfs4_get_clid_cred(struct nfs_client *clp);
 const struct cred *nfs4_get_machine_cred(struct nfs_client *clp);
 const struct cred *nfs4_get_renew_cred(struct nfs_client *clp);

fs/nfs/nfs4proc.c

@@ -5107,12 +5107,12 @@ static bool nfs4_stateid_is_current(nfs4_stateid *stateid,
 		const struct nfs_lock_context *l_ctx,
 		fmode_t fmode)
 {
-	nfs4_stateid current_stateid;
+	nfs4_stateid _current_stateid;
 
 	/* If the current stateid represents a lost lock, then exit */
-	if (nfs4_set_rw_stateid(&current_stateid, ctx, l_ctx, fmode) == -EIO)
+	if (nfs4_set_rw_stateid(&_current_stateid, ctx, l_ctx, fmode) == -EIO)
 		return true;
-	return nfs4_stateid_match(stateid, &current_stateid);
+	return nfs4_stateid_match(stateid, &_current_stateid);
 }
 
 static bool nfs4_error_stateid_expired(int err)

fs/nfs/pnfs.c

@@ -2160,8 +2160,6 @@ out_unlock:
 	return NULL;
 }
 
-extern const nfs4_stateid current_stateid;
-
 static void _lgopen_prepare_attached(struct nfs4_opendata *data,
 				     struct nfs_open_context *ctx)
 {