give a name to the enum to make it easier to reference it in docs; wxFSVolume shouldn't be considered incomplete anymore

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56911 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/chkconf.h

@@ -108,9 +108,12 @@
 #   endif
 #endif /* !defined(wxUSE_FS_ARCHIVE) */
 
-/* don't give an error about this one yet, it's not fully implemented */
 #ifndef wxUSE_FSVOLUME
+#   ifdef wxABORT_ON_CONFIG_ERROR
+#       error "wxUSE_FSVOLUME must be defined."
+#   else
 #       define wxUSE_FSVOLUME 0
+#   endif
 #endif /* !defined(wxUSE_FSVOLUME) */
 
 #ifndef wxUSE_DYNAMIC_LOADER