staging: greybus: camera: Use kcalloc for array's memory allocation.

Fix checkpatch warning:

WARNING: Prefer kcalloc over kzalloc with multiply

kcalloc is designed to allocate memory for arrays, its use is
preferable than kzalloc in these cases.

Signed-off-by: Elise Lennion <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/greybus/camera.c

···
 	if (gb_nstreams > GB_CAMERA_MAX_STREAMS)
 		return -EINVAL;
 
-	gb_streams = kzalloc(gb_nstreams * sizeof(*gb_streams), GFP_KERNEL);
+	gb_streams = kcalloc(gb_nstreams, sizeof(*gb_streams), GFP_KERNEL);
 	if (!gb_streams)
 		return -ENOMEM;
 
···
 		return ret;
 
 	/* For each stream to configure parse width, height and format */
-	streams = kzalloc(nstreams * sizeof(*streams), GFP_KERNEL);
+	streams = kcalloc(nstreams, sizeof(*streams), GFP_KERNEL);
 	if (!streams)
 		return -ENOMEM;