scripts/nvmf_perf: use posix sockets

Use posix sockets by default when running tests.
For now we only want to test with this socket type
and ssl socket support may be added later if needed.

Change-Id: If8b125518cf1c01a841276b58fa7ca7799aeb229
Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14353
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>

scripts/perf/nvmf/run_nvmf.py

@@ -1241,6 +1241,8 @@ class SPDKTarget(Target):
             time.sleep(1)
         self.client = rpc_client.JSONRPCClient("/var/tmp/spdk.sock")
 
+        rpc.sock.sock_set_default_impl(self.client, impl_name="posix")
+
         if self.enable_zcopy:
             rpc.sock.sock_impl_set_options(self.client, impl_name="posix",
                                            enable_zerocopy_send_server=True)