fix the doc names of the return value of swap_dims (#3329)

Author: keewis

xarray/core/dataarray.py

@@ -1453,7 +1453,7 @@ def swap_dims(self, dims_dict: Mapping[Hashable, Hashable]) -> "DataArray":
 
         Returns
         -------
-        renamed : Dataset
+        swapped : Dataset
             DataArray with swapped dimensions.
 
         See Also

xarray/core/dataset.py

@@ -2676,7 +2676,7 @@ def swap_dims(
 
         Returns
         -------
-        renamed : Dataset
+        swapped : Dataset
             Dataset with swapped dimensions.
 
         See Also