Removed the hardcoded php command and moved it to the BENCHMARK_CMD configuration value

Author: blancks

src/config.php

@@ -28,7 +28,7 @@
 /**
  * CLI instruction to run benchmark processes
  */
-const BENCHMARK_CMD = 'jpbench';
+const BENCHMARK_CMD = 'php jpbench';
 
 /**
  * CLI instruction to run automated tests

src/utilities.php

@@ -99,7 +99,7 @@ function spawnProcessFiber(string $library, int $patchsize, int $iterationstart,
     $Fiber = new \Fiber(function(string $library, int $patchsize, int $iterationstart, int $iterationend): void
     {
         $cmd = sprintf(
-            'php %s %s %d %d %d',
+            '%s %s %d %d %d',
             BENCHMARK_CMD,
             $library,
             $patchsize,