Fix the Linux build on Ubuntu 12.04 LTS
Fix the Linux build on Ubuntu 12.04 LTS

This fixes the build, which fails because the initialization values
for an array of struct sigaction cannot be { 0 }.

+ Get rid of warning related to unused return value for ftruncate()

BUG=492
Review URL: https://breakpad.appspot.com/447002

git-svn-id: a14e546401035be51a469fbea25ecce70a1a22f2@1027 4c0a9323-5329-0410-9bdc-e9ce6186880e

tomgr/google-breakpad,tomgr/google-breakpad,tomgr/google-breakpad,tomgr/google-breakpad,tomgr/google-breakpad