[PATCH] diff.c: locate_size_cache() fix.

[PATCH] diff.c: locate_size_cache() fix.

This fixes two bugs.

 - declaration of auto variable "cmp" was preceeded by a
   statement, causing compilation error on real C compilers;
   noticed and patch given by Yoichi Yuasa.

 - the function's calling convention was overloading its size
   parameter to mean "largest possible value means do not add
   entry", which was a bad taste.  Brought up during a
   discussion with Peter Baudis.

Signed-off-by: Junio C Hamano <redacted>
Signed-off-by: Linus Torvalds <redacted>