common: remove erroneous 0x from NATTR_IS* macros
common: remove erroneous 0x from NATTR_IS* macros

Fixes issue #25.

Signed-off-by: Joshua Kahn <c028c213ed5efcf30c3f4fc7361dbde0c893c5b7@joshuak.net>
Signed-off-by: Josef 'Jeff' Sipek <a620f141433c70aa9e43778305a6c68cbfadfb25@josephsipek.net>

jeffpc/nx01