The driver would fail to stop the command timer in most error paths,
something which specifically could lead to the timer being freed while
still active on I/O errors during probe.

Fix this by making sure that each function starting the timer also stops
it in all relevant error paths.

Reported-by:  <syzbot+1d1597a5aa3679c65b9f@syzkaller.appspotmail.com>
Fixes: b78e91bc ("rsi: Add new firmware loading method")
Cc: stable <stable@vger.kernel.org>     # 4.12
Cc: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Cc: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>