net: mscc: ocelot: fix using match before it is set

stable inclusion
from stable-v5.10.94
commit 4496e4a427a03a73de818926946b4bf52579b95f
bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4496e4a427a03a73de818926946b4bf52579b95f

--------------------------------

commit baa59504 upstream.

Clang static analysis reports this issue
ocelot_flower.c:563:8: warning: 1st function call argument
  is an uninitialized value
    !is_zero_ether_addr(match.mask->dst)) {
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The variable match is used before it is set.  So move the
block.

Fixes: 75944fda ("net: mscc: ocelot: offload ingress skbedit and vlan actions to VCAP IS1")
Signed-off-by: NTom Rix <trix@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/net/ethernet/mscc/ocelot_flower.c

@@ -462,13 +462,6 @@ ocelot_flower_parse_key(struct ocelot *ocelot, int port, bool ingress,
 			return -EOPNOTSUPP;
 		}
 
-		if (filter->block_id == VCAP_IS1 &&
-		    !is_zero_ether_addr(match.mask->dst)) {
-			NL_SET_ERR_MSG_MOD(extack,
-					   "Key type S1_NORMAL cannot match on destination MAC");
-			return -EOPNOTSUPP;
-		}
-
 		/* The hw support mac matches only for MAC_ETYPE key,
 		 * therefore if other matches(port, tcp flags, etc) are added
 		 * then just bail out
@@ -483,6 +476,14 @@ ocelot_flower_parse_key(struct ocelot *ocelot, int port, bool ingress,
 			return -EOPNOTSUPP;
 
 		flow_rule_match_eth_addrs(rule, &match);
+
+		if (filter->block_id == VCAP_IS1 &&
+		    !is_zero_ether_addr(match.mask->dst)) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Key type S1_NORMAL cannot match on destination MAC");
+			return -EOPNOTSUPP;
+		}
+
 		filter->key_type = OCELOT_VCAP_KEY_ETYPE;
 		ether_addr_copy(filter->key.etype.dmac.value,
 				match.key->dst);