packfile: remove GIT_DEBUG_LOOKUP log statements

packfile: remove GIT_DEBUG_LOOKUP log statements

In commit 628522ec1439 ("sha1-lookup: more memory efficient search in
sorted list of SHA-1", 2008-04-09), a different algorithm for searching
a sorted list was introduced, together with a set of log statements
guarded by GIT_DEBUG_LOOKUP that are invoked both when using that
algorithm and when using the existing binary search. Those log
statements was meant for experiments and debugging, but with the removal
of the aforementioned different algorithm in commit f1068efefe6d
("sha1_file: drop experimental GIT_USE_LOOKUP search", 2017-08-09),
those log statements are probably no longer necessary.

Remove those statements.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>