[ELF] --wrap: don't copy exportDynamic

For -no-pie/-pie, when `__real_foo` is interposable in a shared object, `foo` is
exported. This rule does not match GNU ld and is unneeded because:

* the exported `foo` does not interpose `__real_foo` at run-time
* the similar `__wrap_foo` <-> `foo` relation does not have the rule