broadcom-wl: fix bash comparison error

This fixes #17495

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 46746

package/kernel/broadcom-wl/files/lib/wifi/broadcom.sh

@@ -218,7 +218,7 @@ enable_broadcom() {
 	}
 
 	local leddc=$(wlc ifname "$device" leddc)
-	[ "$leddc" -eq 0xffff ] || {
+	[ $((leddc)) -eq $((0xffff)) ] && {
 		leddc=0x005a000a;
 	}