ipv4: Calculate multipath hash inside switch statement

A subsequent patch will add another multipath hash policy where the
multipath hash is calculated directly by the policy specific code and
not outside of the switch statement.

Prepare for this change by moving the multipath hash calculation inside
the switch statement.

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -1912,7 +1912,7 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 {
 	u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
 	struct flow_keys hash_keys;
-	u32 mhash;
+	u32 mhash = 0;
 
 	switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
 	case 0:
@@ -1924,6 +1924,7 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 			hash_keys.addrs.v4addrs.src = fl4->saddr;
 			hash_keys.addrs.v4addrs.dst = fl4->daddr;
 		}
+		mhash = flow_hash_from_keys(&hash_keys);
 		break;
 	case 1:
 		/* skb is currently provided only when forwarding */
@@ -1957,6 +1958,7 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 			hash_keys.ports.dst = fl4->fl4_dport;
 			hash_keys.basic.ip_proto = fl4->flowi4_proto;
 		}
+		mhash = flow_hash_from_keys(&hash_keys);
 		break;
 	case 2:
 		memset(&hash_keys, 0, sizeof(hash_keys));
@@ -1987,9 +1989,9 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 			hash_keys.addrs.v4addrs.src = fl4->saddr;
 			hash_keys.addrs.v4addrs.dst = fl4->daddr;
 		}
+		mhash = flow_hash_from_keys(&hash_keys);
 		break;
 	}
-	mhash = flow_hash_from_keys(&hash_keys);
 
 	if (multipath_hash)
 		mhash = jhash_2words(mhash, multipath_hash, 0);