rev-list: fix process_tree() conversion.
rev-list: fix process_tree() conversion.

The tree-walking conversion of the "process_tree()" function
broke packing by using an unrelated variable from outer scope.

Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git