NFS: Remove the left global variable nfs_callback_tcpport

Commit bbe0a3aa "NFS: make nfs_callback_tcpport per network context" has
make nfs_callback_tcpport per network, but left the global nfs_callback_tcpport,
remove it.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/callback.h

@@ -204,6 +204,5 @@ extern int nfs4_set_callback_sessionid(struct nfs_client *clp);
 #define NFS41_BC_MAX_CALLBACKS 1
 
 extern unsigned int nfs_callback_set_tcpport;
-extern unsigned short nfs_callback_tcpport;
 
 #endif /* __LINUX_FS_NFS_CALLBACK_H */

fs/nfs/super.c

@@ -2816,7 +2816,6 @@ static int nfs4_validate_mount_data(void *options,
  * NFS client for backwards compatibility
  */
 unsigned int nfs_callback_set_tcpport;
-unsigned short nfs_callback_tcpport;
 /* Default cache timeout is 10 minutes */
 unsigned int nfs_idmap_cache_timeout = 600;
 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
@@ -2827,7 +2826,6 @@ char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
 bool recover_lost_locks = false;
 
 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
-EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
 EXPORT_SYMBOL_GPL(max_session_slots);