[MachineOutliner][NFC] Remove OccurrenceCount from SuffixTreeNode

After changing the way we find candidates in r346269, this is no longer used.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346275 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed