[media] s5p: fix error code path when failing to allocate DMA memory

In the s5p_mfc_alloc_firmware() function there are some mistakes
where the code checks whether the DMA memory is properly allocated or
not.

First of all dma_alloc_coherent() returns NULL in case of error.
The code also checked two times fw_virt_addr, ignoring
the bank2_virt pointer.
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/s5p-mfc/s5p_mfc_ctrl.c

@@ -38,8 +38,7 @@ int s5p_mfc_alloc_firmware(struct s5p_mfc_dev *dev)
 	dev->fw_virt_addr = dma_alloc_coherent(dev->mem_dev_l, dev->fw_size,
 					&dev->bank1, GFP_KERNEL);
 
-	if (IS_ERR_OR_NULL(dev->fw_virt_addr)) {
-		dev->fw_virt_addr = NULL;
+	if (!dev->fw_virt_addr) {
 		mfc_err("Allocating bitprocessor buffer failed\n");
 		return -ENOMEM;
 	}
@@ -48,7 +47,7 @@ int s5p_mfc_alloc_firmware(struct s5p_mfc_dev *dev)
 		bank2_virt = dma_alloc_coherent(dev->mem_dev_r, 1 << MFC_BASE_ALIGN_ORDER,
 					&bank2_dma_addr, GFP_KERNEL);
 
-		if (IS_ERR(dev->fw_virt_addr)) {
+		if (!bank2_virt) {
 			mfc_err("Allocating bank2 base failed\n");
 			dma_free_coherent(dev->mem_dev_l, dev->fw_size,
 				dev->fw_virt_addr, dev->bank1);