readelf vs. mapping symbols

readelf vs. mapping symbols

This reverts commit 45cf0b829303, which isn't needed after commit
6d7e5bcca5.   Mapping symbols are like any other local symbol, and
shouldn't appear after the end of a section.

The real bug that resulted in both of these commits is that st_value
in an executable or shared library is the symbol address.  It was
wrong to compare an address against a section size (you'd need to
subtract off the section vma first).  The second commit limited the
warning to ET_REL where st_value is a section offset and thus can be
compared directly to the section size.