fix formatting of warning message about unused variables

src/scheduling.ml

@@ -393,10 +393,10 @@ let pp_warning_unused fmt node_schs =
             if vu.var_orig then
               Format.fprintf
                 fmt
-                "  Warning: variable '%s' seems unused@,  %a@,@,"
-                u
+                "   %a       Warning: variable '%s' seems unused@,"
                 Location.pp
-                vu.var_loc)
+                vu.var_loc
+                u)
           unused)
     node_schs