[cmath.syn] Fix hypot(long double,long double) overload

Author: dgrunwald-qt

source/numerics.tex

@@ -10163,7 +10163,7 @@
 
   float hypot(float x, float y);  // see \ref{library.c}
   double hypot(double x, double y);
-  long double hypot(double x, double y);  // see \ref{library.c}
+  long double hypot(long double x, long double y);  // see \ref{library.c}
   float hypotf(float x, float y);
   long double hypotl(long double x, long double y);