staging: unisys: unregister chardev on error

after registering the major numbers if the cdev_add fails then we were
not releasing the major numbers. now we are doing that.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/visorchipset/file.c

@@ -65,8 +65,10 @@ visorchipset_file_init(dev_t major_dev, struct visorchannel **controlvm_channel)
 			return -1;
 	}
 	rc = cdev_add(&file_cdev, MKDEV(MAJOR(major_dev), 0), 1);
-	if (rc  < 0)
+	if (rc < 0) {
+		unregister_chrdev_region(major_dev, 1);
 		return -1;
+	}
 	return 0;
 }