Revert "Fix unit info setting axis label"

This reverts commit 31dee3a.

Author: ksunden

lib/matplotlib/axes/_base.py

@@ -2545,9 +2545,7 @@ def _process_unit_info(self, datasets=None, kwargs=None, *, convert=True):
             except KeyError:
                 raise ValueError(f"Invalid axis name: {axis_name!r}") from None
             # Update from data if axis is already set but no unit is set yet.
-            if (axis is not None and
-                    data is not None and not
-                    axis.have_units_and_converter()):
+            if axis is not None and data is not None and not axis.have_units():
                 axis.update_units(data)
         for axis_name, axis in axis_map.items():
             # Return if no axis is set.

lib/matplotlib/axis.py

@@ -1728,17 +1728,8 @@ def _update_axisinfo(self):
         self.set_default_intervals()
 
     def have_units(self):
-        """
-        Return `True` if units or a converter have been set.
-        """
         return self.converter is not None or self.units is not None
 
-    def have_units_and_converter(self):
-        """
-        Return `True` if units and a converter have been set.
-        """
-        return self.converter is not None and self.units is not None
-
     def convert_units(self, x):
         # If x is natively supported by Matplotlib, doesn't need converting
         if munits._is_natively_supported(x):