selftests: net: lib: Rename ip_link_set_down() to adf_*

Rename this function to mark it as autodefer.
For details, see the discussion in the cover letter.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/e5bf4cb3405fb50fe6e217a04268952e97410dc2.1758821127.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/lib.sh

@@ -595,7 +595,7 @@ adf_ip_link_set_up()
 	fi
 }
 
-ip_link_set_down()
+adf_ip_link_set_down()
 {
 	local name=$1; shift
 

tools/testing/selftests/net/vlan_bridge_binding.sh

@@ -98,7 +98,7 @@ down_netdevs()
 	local dev
 
 	for dev in "$@"; do
-		ip_link_set_down $dev
+		adf_ip_link_set_down $dev
 	done
 }