net: bridge: fdb: restore unlikely() when taking over externally added entries

Taking over hw-learned entries is not a likely scenario so restore the
unlikely() use for the case of SW taking over externally learned
entries.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_fdb.c

@@ -587,8 +587,10 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 				fdb->dst = source;
 				fdb_modified = true;
 				/* Take over HW learned entry */
-				test_and_clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
-						   &fdb->flags);
+				if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
+						      &fdb->flags)))
+					clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
+						  &fdb->flags);
 			}
 			if (now != fdb->updated)
 				fdb->updated = now;