typo fixes

Author: zm711

neo/core/spiketrain.py

@@ -57,7 +57,7 @@ def _check_time_in_range(value, t_start, t_stop, view=False):
     '''
 
     if t_start > t_stop:
-        raise ValueError(f"t_stop ({t_stop}) is before t_start ({s_start})")
+        raise ValueError(f"t_stop ({t_stop}) is before t_start ({t_start})")
 
     if not value.size:
         return

neo/core/spiketrainlist.py

@@ -122,7 +122,7 @@ def __str__(self):
                 return str([])
             else:
                 return (f"SpikeTrainList containing {self._spike_time_array.size} "
-                        f"spikes from {len(self._all_channels_ids)} neurons")
+                        f"spikes from {len(self._all_channel_ids)} neurons")
         else:
             return str(self._items)