eal: simplify exit functions

eal: simplify exit functions

The option RTE_EAL_ALWAYS_PANIC_ON_ERROR was off by default,
and not customizable with meson. It is completely removed.

The function rte_dump_registers is a trace of the bare metal support
era, and was not supported in userland. It is completely removed.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Ray Kinsella <mdr@ashroe.eu>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Kevin Traynor <ktraynor@redhat.com>
Acked-by: David Marchand <david.marchand@redhat.com>