scripts/nvmf_perf: disable sysctl busy_read timeout

Set busy_poll to 0 for non-ADQ. Having it enabled with
this value results is huge latency increase.

Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Change-Id: Ic68ed2b7dc19b8d4b274ce8622194489693863cb
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/7480
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Maciej Wawryk <maciejx.wawryk@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

scripts/perf/nvmf/run_nvmf.py

@@ -173,7 +173,7 @@ class Server:
     def configure_sysctl(self):
         self.log_print("Tuning sysctl settings...")
 
-        busy_read = 50000
+        busy_read = 0
         if self.enable_adq and self.mode == "spdk":
             busy_read = 1