disable a not so good option when allmodconfig is in use

mk/build.mk

@@ -29,6 +29,7 @@ DEFCONFIG=		ADK_DEVELSYSTEM=n \
 			ADK_PACKAGE_LIBHEIMDAL_CLIENT=n \
 			BUSYBOX_BBCONFIG=n \
 			BUSYBOX_SELINUX=n \
+			BUSYBOX_INSTALL_NO_USR=n \
 			BUSYBOX_MODPROBE_SMALL=n \
 			BUSYBOX_EJECT=n \
 			BUSYBOX_BUILD_LIBBUSYBOX=n \