NFS: Use nfs_server_capable() for checknig NFS_CAP_SEEK

This should make the code easier to maintain in the future.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 0886f1d..056f5aa 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -50,7 +50,7 @@
 	struct nfs_server *server = NFS_SERVER(inode);
 	int status;
 
-	if (!(server->caps & NFS_CAP_SEEK))
+	if (!nfs_server_capable(inode, NFS_CAP_SEEK))
 		return -ENOTSUPP;
 
 	status = nfs42_set_rw_stateid(&args.sa_stateid, filep, FMODE_READ);