[ELF] - Remove wrong comment from testcase.

It was introduced by me in D37059.
Comment was saying that Weak binding is incorrect
for 'foo' symbol and that should be true for symbol in final output.
But at that place LTO temporarily file was checked,
where Weak binding for 'foo' is fine as LTO changes binding for
'LinkerRedefined' symbols internally to prevent IPO.

Binding for 'foo' in final output is correctly set to Global
and that tested just few lines below in the same testcase.

llvm-svn: 314204