Revert "Mark UDP socket as ready for write in send msg. (#7927)" (#8027)
Revert "Mark UDP socket as ready for write in send msg. (#7927)" (#8027)

Turns out the code causes that subsequent select()-s never
wait so another solution for the original issue must be
prepared.

This reverts commit 8c555239212ca31160df633fa1e68c5a3c46852b.
nestlabs/connectedhomeip,project-chip/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip