vsprintf: pull updates from Linux kernel

This brings in support for the %p modifier which allows us to easily print
out things like ip addresses, mac addresses, and pointers.

It also converts the rarely used 'q' length modifier to the common 'L'
modifier when dealing with quad types.

While this new code is a bit larger (~1k .text), most of it should be made
up by converting the existing ip/mac address code to use format modifiers.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>