Typo fix in MilliSecondLocator for #35393 (#58788)

Typo fix in MilliSecondLocator for #35393

This locator takes effect when a datetime x-range axis is < 5 seconds
(among a few other conditions), and the typo causes only one xtick
at the very left to be displayed.

pandas/plotting/_matplotlib/converter.py

@@ -430,7 +430,7 @@ def __call__(self):
         freq = f"{interval}ms"
         tz = self.tz.tzname(None)
         st = dmin.replace(tzinfo=None)
-        ed = dmin.replace(tzinfo=None)
+        ed = dmax.replace(tzinfo=None)
         all_dates = date_range(start=st, end=ed, freq=freq, tz=tz).astype(object)
 
         try: