intel/tools: Fix aub_file initialization in intel_dump_gpu

The `device` can be set earlier either by a command line or a by
intercepting an ioctl call to get the I915_PARAM_CHIPSET_ID done by
the application early.  In both cases `aub_file` and `devinfo` would
not be initialized.

Fix by splitting the conditions

- `device == 0`: use the FD to get both device and devinfo.
- Or `devinfo.gen == 0`: use `device` to initialize it.

And separatedly, initialize aub_file the first time it is needed.

Fixes: d594d2a052 ("intel/tools: use device info initializer")
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/intel/tools/intel_dump_gpu.c

@@ -207,6 +207,12 @@ dump_execbuffer2(int fd, struct drm_i915_gem_execbuffer2 *execbuffer2)
       fail_if(!gen_get_device_info_from_fd(fd, &devinfo),
               "failed to identify chipset.\n");
       device = devinfo.chipset_id;
+   } else if (devinfo.gen == 0) {
+      fail_if(!gen_get_device_info_from_pci_id(device, &devinfo),
+              "failed to identify chipset.\n");
+   }
+
+   if (!aub_file.file) {
       aub_file_init(&aub_file, output_file,
                     verbose == 2 ? stdout : NULL,
                     device, program_invocation_short_name);