scripts/nvmf_perf: use standard library logger

Change-Id: I1fa41339ff76fbba97071b62f311699ad870e199
Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14735


Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Kamil Godzwon <kamilx.godzwon@intel.com>
Reviewed-by: Pawel Piatek <pawelx.piatek@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jaroslaw Chachulski <jaroslawx.chachulski@intel.com>
Reviewed-by: Michal Berger <michal.berger@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>