fixup: use \iref

Author: jensmaurer

source/modules.tex

@@ -500,7 +500,7 @@
 it also imports all translation units imported by
 non-exported \grammarterm{module-import-declaration}{s}
 in the module unit purview of $U$.\footnote{This is consistent
-with the rules for visibility of imported names ([basic.scope.namespace]).}
+with the rules for visibility of imported names\iref{basic.scope.namespace}.}
 These rules may in turn lead to the importation of yet more
 translation units.