net: tls: factor out tls_*crypt_async_wait()

commit c57ca512 upstream.

Factor out waiting for async encrypt and decrypt to finish.
There are already multiple copies and a subsequent fix will
need more. No functional changes.

Note that crypto_wait_req() returns wait->err

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: aec79619 ("tls: fix race between async notify and socket close")
[v5.15: removed changes in tls_sw_splice_eof and adjusted waiting factor out for
async descrypt in tls_sw_recvmsg]
Cc: <stable@vger.kernel.org> # 5.15
Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>