ldso: fix _dl_debug_lookup to handle protected symbols
Initialize symbol_ref.sym field before calling _dl_find_hash to correctly
handle protected symbols when tracing objects in the prelink stage.
Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono@st.com>
Signed-off-by: Salvatore Cro <salvatore.cro@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>