Remove a dead check at the end of the configure script that was a left over

Remove a dead check at the end of the configure script that was a left over
from the bzip2 support. This dead check produced the error:
test: -ne: unary operator expected

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18289 91177308-0d34-0410-b5e6-96231b3b80d8