Fix wrong implementation

Fix wrong implementation

If the return value of aul_sock_recv_reply_pkt() is a negative error value,
the function should return the error value after calling aul_error_convert()
with the return value.
Previous implemenation uses the fd variable. It's a wrong implementation.
This patch uses the ret variable when calling aul_error_convert().

Change-Id: Ic054b9d697f9f6502608af88a4ebeed3ae69f138
Signed-off-by: Hwankyu Jhun <h.jhun@samsung.com>