qed: Fix PTT leak in qed_drain()

qed: Fix PTT leak in qed_drain()

BugLink: https://bugs.launchpad.net/bugs/1837161
[ Upstream commit 9aaa4e8ba12972d674caeefbc5f88d83235dd697 ]

Release PTT before entering error flow.

Signed-off-by: Denis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>