tls: rx: jump to a more appropriate label

'recv_end:' checks num_async and decrypted, and is then followed
by the 'end' label. Since we know that decrypted and num_async
are 0 at the start we can jump to 'end'.

Move the init of decrypted and num_async to let the compiler
catch if I'm wrong.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>