add-patch: quit without skipping undecided hunks

add-patch: quit without skipping undecided hunks

Option q implies d, i.e., it marks any undecided hunks towards the
bottom of the hunk array as skipped.  This is unnecessary; later code
treats undecided and skipped hunks the same: The only functions that
use UNDECIDED_HUNK and SKIP_HUNK are patch_update_file() itself (but
not after its big for loop) and its helpers get_first_undecided() and
display_hunks().

Streamline the handling of option q by quitting immediately.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>