staging: goldfish: Change form of NULL comparisons

Change null comparisons of the form x == NULL to !x. This was suggested
by checkpatch.

Signed-off-by: Janani Ravichandran <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/goldfish/goldfish_audio.c

···
 	platform_set_drvdata(pdev, data);
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (r == NULL) {
+	if (!r) {
 		dev_err(&pdev->dev, "platform_get_resource failed\n");
 		return -ENODEV;
 	}
 	data->reg_base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
-	if (data->reg_base == NULL)
+	if (!data->reg_base)
 		return -ENOMEM;
 
 	data->irq = platform_get_irq(pdev, 0);
···
 	}
 	data->buffer_virt = dmam_alloc_coherent(&pdev->dev,
 				COMBINED_BUFFER_SIZE, &buf_addr, GFP_KERNEL);
-	if (data->buffer_virt == NULL) {
+	if (!data->buffer_virt) {
 		dev_err(&pdev->dev, "allocate buffer failed\n");
 		return -ENOMEM;
 	}