libafs: git ignore build artifacts on Solaris

libafs: git ignore build artifacts on Solaris

Ignore build artifacts generated when building the kernel
module for Solaris:

	src/libafs/inet
	src/libafs/nfs
	src/libafs/ufs

Reviewed-on: https://gerrit.openafs.org/12955
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit e0066095e7f74653c2c08d1b00010ba59f4c2cf3)

Change-Id: I5b25a5a4ef6a3b2134daaf848fef9d64b01ee156
Reviewed-on: https://gerrit.openafs.org/13105
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>