When incorrect core value or range provided,
as part of -l command line option, a crash occurs.
Added valid range checks to fix the crash.
Added ut check for negative core values.
Added unit test case for invalid core number range.
Fixes: d888cb8b9613 ("eal: add core list input format")
Cc: stable@dpdk.org
Signed-off-by: Hari Kumar Vemula <hari.kumarx.vemula@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>