tools: kwboot: Initialize rfds to zero

Explicitly zero out the rfds fd_set with FD_ZERO() before using it.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
1 file changed