HID: elo: fix memory leak in elo_probe

When hid_parse() in elo_probe() fails, it forgets to call usb_put_dev to
decrease the refcount.

Fix this by adding usb_put_dev() in the error handling code of elo_probe().

Fixes: fbf42729

 ("HID: elo: update the reference count of the usb device structure")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>