Change all '$(...)' variable references into '${...}'
which makes the environment compatible with the hush shell.
WARNING: Support for the old '$(...)' syntax will be
discontinued in a later version.
diff --git a/board/fads/fads.h b/board/fads/fads.h
index aff1b7e..1127c7f 100644
--- a/board/fads/fads.h
+++ b/board/fads/fads.h
@@ -58,8 +58,8 @@
 #undef	CONFIG_BOOTARGS
 #define CONFIG_BOOTCOMMAND							\
     "dhcp;"									\
-    "setenv bootargs root=/dev/nfs rw nfsroot=$(serverip):$(rootpath) "		\
-    "ip=$(ipaddr):$(serverip):$(gatewayip):$(netmask):$(hostname)::off;"	\
+    "setenv bootargs root=/dev/nfs rw nfsroot=${serverip}:${rootpath} "		\
+    "ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off;"	\
     "bootm"
 
 #undef	CONFIG_WATCHDOG			/* watchdog disabled		*/