devtools: alert on new calls to exit from libs

devtools: alert on new calls to exit from libs

This patch adds a new function that is called
per every checked patch,
and alerts for new instances of rte_panic/rte_exit.
The check excludes comments, and alerts in the case
of a positive balance between additions and removals.

Signed-off-by: Arnon Warshavsky <arnon@qwilt.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Tested-by: Kevin Traynor <ktraynor@redhat.com>