Check the produced file instead of stderr.
Check the produced file instead of stderr.

It is somewhat pointless to check that a specific error is not
produced. That is already checked by the ld.lld exit value.

Instead make the test a bit stronger by checking that the output file
has the expected symbol and section.

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@306496 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld