[PATCH 1 of 2 V2] changectx: increase perf of walk function

[Siddharth Agarwal]

On 01/14/2014 06:00 PM, Durham Goode wrote:
> I originally did that, but largefiles abuses match by setting it's own
> function to match.matchfn and building some state for every matched file
> name. So I still need to call match on hits.

You'll be happy to know that my in-progress revert rewrite's having the 
same issue: it no longer calls the match function for each file being 
reverted in the explicit case, so largefiles doesn't know which files to 
revert. :(