cifs: remove redundant check for null string pointer

server_RFC1001_name is declared as a RFC1001_NAME_LEN_WITH_NULL sized
char array in struct TCP_Server_Info so the null pointer check on
server_RFC1001_name is redundant and can be removed.  Detected with
smatch:

fs/cifs/connect.c:2982 ip_rfc1001_connect() warn: this array is probably
  non-NULL. 'server->server_RFC1001_name'
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/connect.c

@@ -2999,8 +2999,7 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
 	if (ses_init_buf) {
 		ses_init_buf->trailer.session_req.called_len = 32;
 
-		if (server->server_RFC1001_name &&
-		    server->server_RFC1001_name[0] != 0)
+		if (server->server_RFC1001_name[0] != 0)
 			rfc1002mangle(ses_init_buf->trailer.
 				      session_req.called_name,
 				      server->server_RFC1001_name,