Check pointer 'kern->accel_job_ids' for NULL before dereferencing

Pointer 'kern->accel_job_ids' returned from call to function 'acl_malloc' at line 947 may be NULL and will be dereferenced at line 962.

Author: sherry-yuan

src/acl_kernel_if.cpp

@@ -949,6 +949,8 @@ int acl_kernel_if_update(const acl_device_def_autodiscovery_t &devdef,
   if (kern->num_accel > 0) {
     kern->accel_job_ids =
         (int volatile **)acl_malloc(kern->num_accel * sizeof(int *));
+    assert(kern->accel_job_ids);
+
     kern->accel_invoc_queue_depth =
         (unsigned int *)acl_malloc(kern->num_accel * sizeof(unsigned int));