bscan: fix crash on excessive SOS records

Previously the bscan utility crashed when it read a volume that
contained excessive SOS records (i.e. more SOS than EOS records) and was
asked to sync these to the database.
This patch fixes that crash so that volumes with broken SOS/EOS can now
be scanned again.

core/src/stored/bscan.cc

@@ -794,8 +794,6 @@ static bool RecordCb(DeviceControlRecord* dcr, DeviceRecord* rec)
               Pmsg1(0, _("Could not update job record. ERR=%s\n"),
                     db->strerror());
             }
-            mjcr->read_dcr = NULL;
-            FreeJcr(mjcr);
           }
         }
         mr.VolFiles = rec->File;