mpls: fix rtm policy in mpls_getroute

fix rtm policy name typo in mpls_getroute and also remove
export of rtm_ipv4_policy

Fixes: 397fc9e5cefe ("mpls: route get support")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index e17d6cd..bdcfb2d 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -2091,7 +2091,7 @@
 	u8 n_labels;
 
 	err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX,
-			  rtm_ipv4_policy, extack);
+			  rtm_mpls_policy, extack);
 	if (err < 0)
 		goto errout;