staging: unisys: remove unused functions from uislib.c

Delete uislib_client_add_vnic() and uislib_client_delete_vnic(), since these
are never used.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>