test/nvmf: Remove redundant steps from fabrics_fuzz

Also, clear generated fuzz logs upon successful test run - they may
get quite big (> 250MB) in size which doesn't play well with the
artifacts limit CI enforces. If the test succeeded then there's no
point in keeping them around for any potential debugging.

Signed-off-by: Michal Berger <michal.berger@intel.com>
Change-Id: I240e8217cd50dba258310604c6985d8f6a832756
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15030


Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Reviewed-by: Pawel Piatek <pawelx.piatek@intel.com>
Reviewed-by:  <sebastian.brzezinka@intel.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>