Revert "net: tcp: Accept connections only in LISTENING state"

This reverts commit 17ddcc03.

The upstream commit d88f25bd ("net: tcp: Handle special case
where accepted socket is closed") will fix a TCP connection creation
creation properly so this workaround can be reverted.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>