further fix to wait_iface script which first waits until the correspo…

…nding interface sysfs directory exists before checking for the link/carrier.

buildroot-external/package/recovery-system/external/overlay/etc/network/if-pre-up.d/wait_iface

@@ -5,13 +5,15 @@
 # long either. IF_WAIT_DELAY is in seconds.
 
 if [[ -n "${IF_WAIT_DELAY}" ]]; then
-    /sbin/ip link set ${IFACE} up
     printf "Waiting for interface %s to appear" "${IFACE}"
     while [ ${IF_WAIT_DELAY} -gt 0 ]; do
-        CARRIER=$(cat /sys/class/net/${IFACE}/carrier)
-        if [[ -n "${CARRIER}" ]] && [[ ${CARRIER} -eq 1 ]]; then
-            printf "\n"
-            exit 0
+        if [[ -d "/sys/class/net/${IFACE}" ]]; then
+            /sbin/ip link set ${IFACE} up
+            CARRIER=$(cat /sys/class/net/${IFACE}/carrier)
+            if [[ -n "${CARRIER}" ]] && [[ ${CARRIER} -eq 1 ]]; then
+                printf "\n"
+                exit 0
+            fi
         fi
         sleep 1
         printf "."