brcm63xx-arm: fix media type setting with autonegotiation disabled

Commit 7d1285b6 introduced an issue with setting media type for a particular port when
autonegotiation is disabled. In this case $subport ends up being undefined, resulting in an error in ethctl, which
leads to the appropriate media type not being set.

This change is designed to fix the above. Additionally cleaned up the conditionals a bit, so that media type is only
determined once and then reused regardless of whether "oncrossbar" is set or not.

Related to IOP-6415
Related to IOP-5001

iopsys-brcm63xx-arm/base-files/lib/network/port.sh

@@ -43,7 +43,7 @@ set_port_settings() {
 	local autoneg=$5
 	local eee=$6
 	local pause=$7
-	local crossbarports
+	local crossbarports media_type
 
 	[ -d /sys/class/net/$ifname ] || return
 
@@ -56,22 +56,20 @@ set_port_settings() {
 	[ "$duplex" == 0 ] && dplx="HD" || dplx="FD"
 	crossbar="$(echo `ethctl $ifname phy-crossbar` | awk -F' ' '{ print $2 $3 }')"
 
+	if [ "$autoneg" = "on" ]; then
+		media_type="auto"
+	else
+		media_type="$speed$dplx"
+	fi
+
 	if [ "$crossbar" == "oncrossbar" ]; then
 		crossbarports="$(echo `ethctl $ifname phy-crossbar` | awk -F':' '{ print $NF }')"
 
-		if [ "$autoneg" == "on" ]; then
-			for subport in $crossbarports; do
-				ethctl $ifname media-type auto port $subport &>/dev/null
-			done
-		else
-			ethctl $ifname media-type $speed$dplx port $subport &>/dev/null
-		fi
+		for subport in $crossbarports; do
+			ethctl $ifname media-type $media_type port $subport &>/dev/null
+		done
 	else
-		if [ "$autoneg" == "on" ]; then
-			ethctl $ifname media-type auto &>/dev/null
-		else
-			ethctl $ifname media-type $speed$dplx &>/dev/null
-		fi
+		ethctl $ifname media-type $media_type &>/dev/null
 	fi
 
 	[ $eee -eq 1 ] && eee="on" || eee="off"