[rand.req.{eng,dist}] Replace square brackets around reference with regular parentheses. (#1481)

Author: Eelis

source/numerics.tex

@@ -2046,7 +2046,7 @@
     ensures that \tcode{v}'s state is unchanged by the operation
     and
     calls \tcode{is.setstate(ios::failbit)}
-    (which may throw \tcode{ios::failure}~[\ref{iostate.flags}]).
+    (which may throw \tcode{ios::failure}~(\ref{iostate.flags})).
     If a textual representation written via \tcode{os << x}
     was subsequently read via \tcode{is >> v},
     then \tcode{x == v}
@@ -2433,7 +2433,7 @@
     ensures that \tcode{d} is unchanged by the operation
     and
     calls \tcode{is.setstate(ios::failbit)}
-    (which may throw \tcode{ios::failure}~[\ref{iostate.flags}]).
+    (which may throw \tcode{ios::failure}~(\ref{iostate.flags})).
 
     \requires \tcode{is} provides a textual representation
     that was previously written