[Arista] Fix arista-net initramfs hook (#10624)

The interface renaming logic fails if one interface is missing.
Because of the `set -e` the whole initramfs hook would abort early on
error.
This change fixes the current behavior to make sure missing interfaces
are properly skipped and ensure existing interface are renamed.

files/initramfs-tools/arista-net

@@ -47,7 +47,9 @@ arista_net_rename() {
     local new_name="$2"
     local from_name="$3"
     devname=$(arista_net_devname "$device_path" "$from_name")
-    [ -n "$devname" ] && ip link set "$devname" name "$new_name"
+    if [ -n "$devname" ]; then
+        ip link set "$devname" name "$new_name"
+    fi
 }
 
 # Sets the MAC address to the value passed by Aboot through /proc/cmdline