Redis redis-benchmark silently fails on unknown Redis commands

For example:

$ redis-benchmark -n 1 -c 1 foo
====== foo ======
  1 requests completed in 0.00 seconds
  1 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
inf requests per second

Note - also tested with other non-commands, with the same results:

- $ redis-benchmark -n 1 -c 1 foo
+ $ redis-benchmark -n 1 -c 1 moo

Comment From: filipecosta90

@itamarhaber closing this one given it was fixed by https://github.com/redis/redis/pull/8869 =)