Fixup: LWG3112: use \newline instead of \hfill\break

Author: Dawn Perchik

source/diagnostics.tex

@@ -1702,7 +1702,7 @@
 \effects Constructs an object of class \tcode{system_error}.
 
 \pnum
-\ensures \tcode{code() == ec} and\hfill\break % avoid Overfull
+\ensures \tcode{code() == ec} and\newline
 \tcode{string_view(what()).find(what_arg.c_str()) != string_view::npos}.
 \end{itemdescr}