ipv4: Remove redundant RCU locking in ip_check_mc().

All callers are under rcu_read_lock() protection already.

Rename to ip_check_mc_rcu() to make it even more clear.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 44ba906..12b65cc 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2333,13 +2333,13 @@
 	rtnl_unlock();
 }
 
-int ip_check_mc(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
+/* called with rcu_read_lock() */
+int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
 {
 	struct ip_mc_list *im;
 	struct ip_sf_list *psf;
 	int rv = 0;
 
-	rcu_read_lock();
 	for_each_pmc_rcu(in_dev, im) {
 		if (im->multiaddr == mc_addr)
 			break;
@@ -2361,7 +2361,6 @@
 		} else
 			rv = 1; /* unspecified source; tentatively allow */
 	}
-	rcu_read_unlock();
 	return rv;
 }