[Ada] Correct usage of Default_Aspect_Value in scalar types

[Arnaud Charlet]

This patch corrects the string representation of attribute Default_Aspect_Value
when it is applied to scalar types. The string name is for internal debugging
purposes only, no test.

Tested on x86_64-pc-linux-gnu, committed on trunk

2013-10-10  Hristian Kirtchev  <kirtc...@adacore.com>

        * einfo.adb (Write_Field19_Name): Correct the
        string name of attribute Default_Aspect_Value.


Index: einfo.adb
===================================================================
--- einfo.adb   (revision 203368)
+++ einfo.adb   (working copy)
@@ -8741,7 +8741,7 @@
             Write_Str ("Corresponding_Discriminant");
 
          when Scalar_Kind                                  =>
-            Write_Str ("Default_Value");
+            Write_Str ("Default_Aspect_Value");
 
          when E_Array_Type                                 =>
             Write_Str ("Default_Component_Value");