Merge branch 'ipv4-routing-cleanups'

Alexander Duyck says:

====================
Minor IPv4 routing cleanups

These patches just contain some minor cleanups to address a few minor
issues.  The first and the third mostly just improve readability.  The
second patch should improve the performance for multicast destination
addresses that do not have a localhost source IP address by avoiding some
unnecessary dereferences.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>