[zlib] Add catch-all #else to chunkcopy_safe_ugly

Otherwise the function fails to do any copying in compiles which doesn't
hit the cases above.

Bug: 1103818
Change-Id: I18b99488df6852e3713c6b2dc7ae268eceedee52
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2336075


Commit-Queue: Adenilson Cavalcanti <cavalcantii@chromium.org>
Reviewed-by: Adenilson Cavalcanti <cavalcantii@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#794570}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e7217f74f1d8af8be68d796686c414c12904c549