sancov.py: [Py3] Use '//' instead of '/' as division operator.
sancov.py: [Py3] Use '//' instead of '/' as division operator.

Py3 emits float with '/'.

This is part of https://reviews.llvm.org/D27405

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@294306 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt