Fix typo in docstring.

IPython/core/magics/execution.py

@@ -1060,7 +1060,7 b' python-profiler package from non-free.""")'
           following statement raises an error).
 
         This function provides very basic timing functionality.  Use the timeit 
-        magic for more controll over the measurement.
+        magic for more control over the measurement.
 
         Examples
         --------