selftests: mlxsw: qos_mc_aware: Specify arping timeout as an integer

Starting from iputils s20190709 (used in Fedora 31), arping does not
support timeout being specified as a decimal:

$ arping -c 1 -I swp1 -b 192.0.2.66 -q -w 0.1
arping: invalid argument: '0.1'

Previously, such timeouts were rounded to an integer.

Fix this by specifying the timeout as an integer.

Fixes: a5ee171d087e ("selftests: mlxsw: qos_mc_aware: Add a test for UC awareness")
Signed-off-by: Amit Cohen <[e-mail]>
Reviewed-by: Petr Machata <[e-mail]>
Signed-off-by: Ido Schimmel <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh

···
 	local i
 
 	for ((i = 0; i < attempts; ++i)); do
-		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 0.1; then
+		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 1; then
 			((passes++))
 		fi