[time.cal.ymwd.members] Fix object name in year_month_weekday constructor (#4304)

Author: faithandbrave

source/time.tex

@@ -7209,9 +7209,9 @@
 
 \pnum
 \remarks
-For any value \tcode{ymdl} of type \tcode{year_month_weekday}
-for which \tcode{ymdl.ok()} is \tcode{true},
-\tcode{ymdl == year_month_weekday\{sys_days\{ymdl\}\}} is \tcode{true}.
+For any value \tcode{ymwd} of type \tcode{year_month_weekday}
+for which \tcode{ymwd.ok()} is \tcode{true},
+\tcode{ymwd == year_month_weekday\{sys_days\{ymwd\}\}} is \tcode{true}.
 \end{itemdescr}
 
 \indexlibraryctor{year_month_weekday}%