net/tls: Fix another skb memory leak when running kTLS traffic

This patch is a followup to
commit ffef737f ("net/tls: Fix skb memory leak when running kTLS traffic")

Which was missing another sk_defer_free_flush() call in
tls_sw_splice_read().

Fixes: f35f8219 ("tcp: defer skb freeing after socket lock is released")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>