drivers/acpi: use kasprintf

kasprintf combines kmalloc and sprintf, and takes care of the size
calculation itself.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression a,flag;
expression list args;
statement S;
@@

  a =
-  \(kmalloc\|kzalloc\)(...,flag)
+  kasprintf(flag,args)
  <... when != a
  if (a == NULL || ...) S
  ...>
- sprintf(a,args);
// </smpl>

[akpm@linux-foundation.org: don't change handling of `count']
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/video.c

@@ -1007,11 +1007,11 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
 		result = acpi_video_init_brightness(device);
 		if (result)
 			return;
-		name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
+		name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
 		if (!name)
 			return;
+		count++;
 
-		sprintf(name, "acpi_video%d", count++);
 		memset(&props, 0, sizeof(struct backlight_properties));
 		props.max_brightness = device->brightness->count - 3;
 		device->backlight = backlight_device_register(name, NULL, device,
@@ -1067,10 +1067,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
 		if (device->cap._DCS && device->cap._DSS) {
 			static int count;
 			char *name;
-			name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
+			name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
 			if (!name)
 				return;
-			sprintf(name, "acpi_video%d", count++);
+			count++;
 			device->output_dev = video_output_register(name,
 					NULL, device, &acpi_output_properties);
 			kfree(name);