Fix a couple of (AFAICS false) may-be-used-uninitialized warnings that show up
on the OSX 10.5 buildbot.

Change-Id: I49e066feab8b980ea85371095234e96e89db71e1
Reviewed-on: https://code.wireshark.org/review/5247
Reviewed-by: Jeff Morriss <jeff.morriss.ws@gmail.com>