USB: gadget: f_mass_storage: put_device() in error recovery

This commit fixes an issue with error recovery after
device_register() fails in Mass Storage Function.  The device
needs to be put to avoid resource leakage.
Signed-off-by: Rahul Ruikar <rahul.ruikar@gmail.com>
[mina86@mina86.com: updated commit message]
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/f_mass_storage.c

@@ -2765,6 +2765,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 		if (rc) {
 			INFO(common, "failed to register LUN%d: %d\n", i, rc);
 			common->nluns = i;
+			put_device(&curlun->dev);
 			goto error_release;
 		}