Fix name of variable in doc string

Author: konrad

lib/matplotlib/axes/_axes.py

@@ -2928,7 +2928,7 @@ def boxplot(self, x, notch=False, sym=None, vert=True, whis=1.5,
             The default symbol for flier points.
             Enter an empty string ('') if you don't want to show fliers.
             If `None`, then the fliers default to 'b+'  If you want more
-            control use the fliersprop kwarg.
+            control use the flierprops kwarg.
 
           vert : bool, default = True
             If True (default), makes the boxes vertical.