media: s5p-mfc: Adjust a null pointer check in four functions

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written...

Thus fix the affected source code places.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/s5p-mfc/s5p_mfc.c

@@ -470,7 +470,7 @@ static void s5p_mfc_handle_error(struct s5p_mfc_dev *dev,
 {
 	mfc_err("Interrupt Error: %08x\n", err);
 
-	if (ctx != NULL) {
+	if (ctx) {
 		/* Error recovery is dependent on the state of context */
 		switch (ctx->state) {
 		case MFCINST_RES_CHANGE_INIT:
@@ -508,7 +508,7 @@ static void s5p_mfc_handle_seq_done(struct s5p_mfc_ctx *ctx,
 {
 	struct s5p_mfc_dev *dev;
 
-	if (ctx == NULL)
+	if (!ctx)
 		return;
 	dev = ctx->dev;
 	if (ctx->c_ops->post_seq_start) {
@@ -562,7 +562,7 @@ static void s5p_mfc_handle_init_buffers(struct s5p_mfc_ctx *ctx,
 	struct s5p_mfc_buf *src_buf;
 	struct s5p_mfc_dev *dev;
 
-	if (ctx == NULL)
+	if (!ctx)
 		return;
 	dev = ctx->dev;
 	s5p_mfc_hw_call(dev->mfc_ops, clear_int_flags, dev);
@@ -1289,7 +1289,7 @@ static int s5p_mfc_probe(struct platform_device *pdev)
 		return PTR_ERR(dev->regs_base);
 
 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (res == NULL) {
+	if (!res) {
 		dev_err(&pdev->dev, "failed to get irq resource\n");
 		return -ENOENT;
 	}