cifs: fix unneeded null check

tcon can not be null in SMB2_tcon function so the check
is not relevant and removing it makes Coverity happy.
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Addresses-Coverity: 13250131 ("Dereference before null check")
Signed-off-by: NSteve French <stfrench@microsoft.com>

fs/cifs/smb2pdu.c

@@ -1779,10 +1779,8 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 	rsp = (struct smb2_tree_connect_rsp *)rsp_iov.iov_base;
 	trace_smb3_tcon(xid, tcon->tid, ses->Suid, tree, rc);
 	if (rc != 0) {
-		if (tcon) {
-			cifs_stats_fail_inc(tcon, SMB2_TREE_CONNECT_HE);
-			tcon->need_reconnect = true;
-		}
+		cifs_stats_fail_inc(tcon, SMB2_TREE_CONNECT_HE);
+		tcon->need_reconnect = true;
 		goto tcon_error_exit;
 	}