[PATCH] uml: avoid unnecessary pcap rebuild

Just a Kbuild subtlety, not listing a target file inside targets causes it
to be rebuilt each time, and as a consequence everything depending on it is
rebuilt.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>