net: fix infoleak in rtnetlink

The stack object “map” has a total size of 32 bytes. Its last 4
bytes are padding generated by compiler. These padding bytes are
not initialized and sent out via “nla_put”.

Conflicts:
	net/core/rtnetlink.c

b/28620102
Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dennis Cagle <d-cagle@codeaurora.org>
Git-commit: 5f8e44741f9f216e33736ea4ec65ca9ac03036e6
Git-repo: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git
(cherry picked from commit 5f8e44741f9f216e33736ea4ec65ca9ac03036e6)
Change-Id: I41f4745f24720c7af5ab08dc4274224d7fe4dcfe