merge-recursive: Fix multiple file rename across D/F conflict

merge-recursive: Fix multiple file rename across D/F conflict

In 5a2580d (merge_recursive: Fix renames across paths below D/F conflicts
2010-07-09), detection was added for renames across paths involved in a
directory<->file conflict.  However, the change accidentally involved
reusing an outer loop index ('i') in an inner loop, changing its values
and causing a slightly different type of breakage for cases where there are
multiple renames across the D/F conflict.  Fix by creating a new temporary
variable 'i'.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>