[arcmt] When fixing the "unassigned init call" ARC error, make sure
to do a nil check for the result of the call.

rdar://10950973

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153793 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed