firmware-gsmi: Delete an unnecessary check before the function call "dma_pool_destroy"

The dma_pool_destroy() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <[e-mail]>
Cc: Greg KH <[e-mail]>
Cc: Julia Lawall <[e-mail]>
Cc: Mike Waychison <[e-mail]>
Cc: Michel Lespinasse <[e-mail]>
Signed-off-by: Matt Fleming <[e-mail]>

drivers/firmware/google/gsmi.c

···
 	gsmi_buf_free(gsmi_dev.param_buf);
 	gsmi_buf_free(gsmi_dev.data_buf);
 	gsmi_buf_free(gsmi_dev.name_buf);
-	if (gsmi_dev.dma_pool)
-		dma_pool_destroy(gsmi_dev.dma_pool);
+	dma_pool_destroy(gsmi_dev.dma_pool);
 	platform_device_unregister(gsmi_dev.pdev);
 	pr_info("gsmi: failed to load: %d\n", ret);
 	return ret;