[dcl.decl.general] Fix cross-references

"templated function" is defined in [temp.pre], but avoid having
two cross-references to the same place in the same paragraph by
dropping the cross-reference for the definition of the grammar
non-terminal "requires-clause".

Author: jensmaurer

source/declarations.tex

@@ -2165,10 +2165,10 @@
 \end{note}
 
 \pnum
-The optional \grammarterm{requires-clause}\iref{temp.pre} in an
+The optional \grammarterm{requires-clause} in an
 \grammarterm{init-declarator} or \grammarterm{member-declarator}
 shall be present only if the declarator declares a
-templated function\iref{dcl.fct}.
+templated function\iref{temp.pre}.
 %
 \indextext{trailing requires-clause@trailing \gterm{requires-clause}|see{\gterm{requires-clause}, trailing}}%
 When present after a declarator, the \grammarterm{requires-clause}