ssa.c: Release GError object where appropriate

From https://developer.gnome.org/gconf/stable/gconf-gconf-error.html
If an error occurs, a GError will be allocated and placed
in the return location; the caller must free the GError
with g_error_free().

Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>