[PATCH] Avoid unnecessarily inflating and interpreting delta

[PATCH] Avoid unnecessarily inflating and interpreting delta

This teaches packed_delta_info() that it only needs to look at
the type of the base object to figure out both type and size of
a deltified object.  This saves quite a many calls to inflate()
when dealing with a deep delta chain.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>