PR22303, print_core_note out of bounds read

PR22303, print_core_note out of bounds read

The print_core_note change here fixes the PR, the rest is making
readelf a little more bombproof against maliciously crafted binaries.

	PR 22303
	* readelf.c (print_core_note): Ensure "count" sanity check
	calculation doesn't overflow.
	(process_notes_at): Perform note namesz and descsz checks
	using unsigned comparisons against data remaining.  Catch
	alignment overflow of namesz and descsz too.  Don't allocate a
	temp for terminating "name" when there is space available
	before descdata.