Fix FIXME: xstrdup should not be here

Fix FIXME: xstrdup should not be here

Hi,

This FIXME goes into my eyes, when I am about to modify something here,

  /* Name is allocated by name_of_child.  */
  /* FIXME: xstrdup should not be here.  */

This FIXME was introduced in the python pretty-pretter patches.

  Python pretty-printing [6/6]
  https://sourceware.org/ml/gdb-patches/2009-05/msg00467.html

create_child_with_value is called in two paths,

 1. varobj_list_children -> create_child -> create_child_with_value,
 2. install_dynamic_child -> install_dynamic_child -> varobj_add_child
    -> create_child_with_value

In path #1, 'name' is allocated by name_of_child, as the original
comment said, we don't have to duplicate NAME in
create_child_with_value.  In path #2, 'name' is got from
PyArg_ParseTuple, and we have to duplicate NAME.

This patch removes the call to xstrdup in create_child_with_value
and call xstrudp in update_dynamic_varobj_children (path #2).

gdb:

2013-10-04  Yao Qi  <yao@codesourcery.com>

	* varobj.c (create_child_with_value): Remove 'const' from the
	type of parameter 'name'.
	(varobj_add_child): Likewise.
	(install_dynamic_child): Remove 'const' from the type of
	parameter 'name'.
	(varobj_add_child): Likewise.
	(create_child_with_value): Likewise.  Update comments.  Don't
	duplicate 'name'.
	(update_dynamic_varobj_children): Duplicate 'name'
	and pass it to install_dynamic_child.