LU-18779 lnet: lnetctl SIGSEGV in lnetctl.c getopt_internal()

LU-18779 lnet: lnetctl SIGSEGV in lnetctl.c getopt_internal()

Variable optindex was out of range. The whole check could be
simplified (only check optarg) if no negative values for verbose
 are expected. Also modified for peer.

Test-Parameters: trivial
Signed-off-by: Frank Sehr <fsehr@whamcloud.com>
Change-Id: I64aad7527377b098479e93040a84b0865b02de28
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/58322
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Manish Regmi <mregmi@ddn.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>