rootfs: correct rootfs script deference var value
shell usage function use wrong way to get AGENT_BIN value
Fixes
@@ -58,7 +58,7 @@ GO_AGENT_PKG: Change the golang package url to get the agent source code
AGENT_BIN : Name of the agent binary (needed to check if agent is installed)
USE_DOCKER: If set will build rootfs in a Docker Container (requries docker)
DEFAULT: not set
-AGENT_INIT : Use $(AGENT_BIN) as init process.
+AGENT_INIT : Use ${AGENT_BIN} as init process.
DEFAULT: no
KERNEL_MODULES_DIR: Optional kernel modules to put into the rootfs.
DEFAULT: ""
