port 11185 from 1.1: Fix names in documentation

doc/doxygen/chapters/api/codelet_and_tasks.doxy

@@ -412,25 +412,25 @@ application through <c>malloc()</c>, setting starpu_task::callback_arg_free
 to 1 makes StarPU automatically call <c>free(callback_arg)</c> when
 destroying the task.
 
-\var starpu_task::prologue_func
+\var starpu_task::prologue_callback_func
 Optional field, the default value is <c>NULL</c>. This is a function
 pointer of prototype <c>void (*f)(void *)</c> which specifies a
 possible callback. 
 If this pointer is non-null, the callback function
 is executed on the host when the task becomes ready for execution,
 before getting scheduled. The callback is passed the
-value contained in the starpu_task::prologue_arg field. No callback is
+value contained in the starpu_task::prologue_callback_arg field. No callback is
 executed if the field is set to NULL.
 
-\var starpu_task::prologue_arg (optional) (default: NULL)
+\var starpu_task::prologue_callback_arg (optional) (default: NULL)
 Optional field, the default value is <c>NULL</c>. This is the pointer
-passed to the prologue function. This field is ignored if the field
-starpu_task::prologue_func is set to <c>NULL</c>.
+passed to the prologue callback function. This field is ignored if the field
+starpu_task::prologue_callback_func is set to <c>NULL</c>.
 
-\var starpu_task::prologue_callback__arg_free
-Optional field. In case starpu_task::prologue_callback__arg was allocated by the
-application through <c>malloc()</c>, setting starpu_task::prologue_callback__arg_free
-to 1 makes StarPU automatically call <c>free(prologue_callback__arg)</c> when
+\var starpu_task::prologue_callback_arg_free
+Optional field. In case starpu_task::prologue_callback_arg was allocated by the
+application through <c>malloc()</c>, setting starpu_task::prologue_callback_arg_free
+to 1 makes StarPU automatically call <c>free(prologue_callback_arg)</c> when
 destroying the task.
 
 \var starpu_task::use_tag