t1405: sort reflog entries in a hash-independent way

t1405: sort reflog entries in a hash-independent way

The test enumerates reflog entries in an arbitrary order and then sorts
them.  For SHA-1, this produces results that happen to sort in
alphabetical order, but for other hash algorithms they sort differently.
Ensure we sort the reflog entries in a hash-independent way by sorting
on the ref name instead of the object ID.  Remove an assumption about
the length of a hash by using cut with the delimiter and field options
instead of the character range option.

Signed-off-by: brian m. carlson <redacted>
Signed-off-by: Junio C Hamano <redacted>