media: staging: atomisp: fix string comparation logic

it makes no sense to use strncmp() with a size with is
bigger than the string we're comparing with.

Fix those warnings:

    drivers/staging/media/atomisp/pci/atomisp2/atomisp_fops.c:776 atomisp_open() error: strncmp() '"ATOMISP ISP ACC"' too small (16 vs 32)
    drivers/staging/media/atomisp/pci/atomisp2/atomisp_fops.c:913 atomisp_release() error: strncmp() '"ATOMISP ISP ACC"' too small (16 vs 32)
    drivers/staging/media/atomisp/pci/atomisp2/atomisp_ioctl.c:2751 atomisp_vidioc_default() error: strncmp() '"ATOMISP ISP ACC"' too small (16 vs 32)
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/staging/media/atomisp/pci/atomisp2/atomisp_fops.c

@@ -773,8 +773,7 @@ static int atomisp_open(struct file *file)
 
 	rt_mutex_lock(&isp->mutex);
 
-	acc_node = !strncmp(vdev->name, "ATOMISP ISP ACC",
-			sizeof(vdev->name));
+	acc_node = !strcmp(vdev->name, "ATOMISP ISP ACC");
 	if (acc_node) {
 		acc_pipe = atomisp_to_acc_pipe(vdev);
 		asd = acc_pipe->asd;
@@ -910,8 +909,7 @@ static int atomisp_release(struct file *file)
 	rt_mutex_lock(&isp->mutex);
 
 	dev_dbg(isp->dev, "release device %s\n", vdev->name);
-	acc_node = !strncmp(vdev->name, "ATOMISP ISP ACC",
-			sizeof(vdev->name));
+	acc_node = !strcmp(vdev->name, "ATOMISP ISP ACC");
 	if (acc_node) {
 		acc_pipe = atomisp_to_acc_pipe(vdev);
 		asd = acc_pipe->asd;

drivers/staging/media/atomisp/pci/atomisp2/atomisp_ioctl.c

@@ -2748,8 +2748,7 @@ static long atomisp_vidioc_default(struct file *file, void *fh,
 	bool acc_node;
 	int err;
 
-	acc_node = !strncmp(vdev->name, "ATOMISP ISP ACC",
-			sizeof(vdev->name));
+	acc_node = !strcmp(vdev->name, "ATOMISP ISP ACC");
 	if (acc_node)
 		asd = atomisp_to_acc_pipe(vdev)->asd;
 	else