Base check on the section name, not the variable name.

The variable is private, so the name should not be relied on. Also, the
linker uses the sections, so asan should too when trying to avoid causing
the linker problems.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221480 91177308-0d34-0410-b5e6-96231b3b80d8