Documentation: bonding: correct xmit hash steps

Correct xmit hash steps for layer3+4 as introduced by commit
49aefd13 ("bonding: do not discard lowest hash bit for non layer3+4
hashing").
Signed-off-by: Jonathan Toppins <jtoppins@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/bonding.rst

@@ -957,6 +957,7 @@ xmit_hash_policy
 		hash = hash XOR source IP XOR destination IP
 		hash = hash XOR (hash RSHIFT 16)
 		hash = hash XOR (hash RSHIFT 8)
+		hash = hash RSHIFT 1
 		And then hash is reduced modulo slave count.
 
 		If the protocol is IPv6 then the source and destination