tls: rx: refactor decrypt_skb_update()

[ Upstream commit 3764ae5b ]

Use early return and a jump label to remove two indentation levels.
No functional changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: f7fa16d4 ("tls: decrement decrypt_pending if no async completion will be called")
Signed-off-by: Sasha Levin <sashal@kernel.org>