[PowerPC] Remove wild call to RegScavenger::initRegState().

This call should in fact be made by RegScavenger::enterBasicBlock()
called below. The first call does nothing except for triggering UB,
indicated by UBSan (passing nullptr to memset()).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254548 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed