PR22216, infinite loop in readelf process_symbol_table

PR22216, infinite loop in readelf process_symbol_table

This should make readelf bombproof given a fuzzed DT_HASH.  Also
removes a bogus check that would have resulted in wrong histograms.

	PR 22216
	* readelf.c (process_symbol_table): Check that DT_HASH symbol
	chains are only visited once, and report an error if not.  Display
	invalid symbol index if chain is out of range.  Use the same logic
	when calculating histograms rather than the PR 17531 fix.  Delete
	bogus check that chained index is less than number of buckets.