package/smcroute: bump version to v2.5.3

- Upstream has .sha256 checksum files, drop redundant .md5 checksum
 - Backport upstream patch to silence bogus error message for loopback
 - SMCRoute is useless w/o kernel support, use same fixups as mrouted

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>