Some style and whitespace fixes.  Reduce the difference between geom_uzip(4)
and geom_uncompress(4).  Now, they produce an almost clean diff(1) output.

Remove a duplicated variable from g_uncompress.c and an unnecessary header
from g_uzip.c.

No functional changes.
Actually the FEATURE() macro is defined on sys/sysctl.h.

Pointyhat to:	loos
Fix rnh_walktree_from() function (patch from kern/174959).
Require valid netmask to be passed since host route is always a leaf.

PR:		kern/174959
Submitted by:	Keith Sklower
MFC after:	2 weeks