Mac: Fix shadow warning
Mac: Fix shadow warning

This caused a warning with `-Wshadow` on due to the loop below.

Bug: None
Change-Id: I63c4252d7ff66c416d8f0edde868a9b0a6aeb65e
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3838745
Reviewed-by: Mark Mentovai <f1b5a91d4d6ad523f2610114591c007e75d15084@chromium.org>
Commit-Queue: Leonard Grey <e5b5c691cb6db945fe90ad6ef1a941cf4374b444@chromium.org>

chromium/crashpad,chromium/crashpad,chromium/crashpad