upload-pack: pass upload_pack_data to deepen_by_rev_list()

upload-pack: pass upload_pack_data to deepen_by_rev_list()

As we cleanup 'upload-pack.c' by using 'struct upload_pack_data'
more thoroughly, let's pass that struct to deepen_by_rev_list(),
so that this function can use all the fields of the struct.

This will be used in followup commits to move static variables
into 'upload_pack_data'.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>