Revert "misc: Validate the value on the use of strtol."

* g10/misc.c: No checking for end-of-string after strtol because the
function is also used for strings with several values.

Reverts-commit: bcd87ea2b2da3ed9fe41341959d9c886029606a9

The int-overflow is anyway if - overrated you own the command line you
own everything.

• GnuPG-bug-id: T7909