Fix workspace tool name property

The fallback tool was used as the tool name.

Regression in a8ce9a143a

source/blender/makesrna/intern/rna_workspace.c

@@ -272,7 +272,6 @@ static void rna_def_workspace_tool(BlenderRNA *brna)
 
   prop = RNA_def_property(srna, "idname_fallback", PROP_STRING, PROP_NONE);
   RNA_def_property_ui_text(prop, "Identifier Fallback", "");
-  RNA_def_struct_name_property(srna, prop);
 
   prop = RNA_def_property(srna, "index", PROP_INT, PROP_NONE);
   RNA_def_property_clear_flag(prop, PROP_EDITABLE);