src/dvbpsi.c: fix segmentation fault in dvbpsi_decoder_psi_section_add()

When p->i_number == p_section->i_number AND p_prev == NULL, then the
first element of the list has to be replaced. Since it is the first
element we have to update the pointer to the list, which is pointing to
the first element
Signed-off-by: Jean-Paul Saman <jpsaman@videolan.org>

src/dvbpsi.c

@@ -272,6 +272,7 @@ bool dvbpsi_decoder_psi_section_add(dvbpsi_decoder_t *p_decoder, dvbpsi_psi_sect
                 p->p_next = NULL;
                 dvbpsi_DeletePSISections(p);
                 p = p_section;
+                p_decoder->p_sections = p;
                 b_overwrite = true;
             }
             goto out;