Refactor error logging

It is hard to grep errors in current log. so in this patch,
I'm updating die function which also writes log for
screen_log_dir/error.log.
In future, we may categolize negative fault by using
this error.log.

Change-Id: I70a8cfe67ed408284f5c88c762c6bb8acb8ecdb2
diff --git a/lib/rpc_backend b/lib/rpc_backend
index f35f9db..7ea71ee 100644
--- a/lib/rpc_backend
+++ b/lib/rpc_backend
@@ -39,8 +39,7 @@
     fi
 
     if is_service_enabled qpid && ! qpid_is_supported; then
-        echo "Qpid support is not available for this version of your distribution."
-        exit 1
+        die $LINENO "Qpid support is not available for this version of your distribution."
     fi
 }