patch 8.2.4241: some type casts are redundant

Problem:    Some type casts are redundant.
Solution:   Remove the type casts. (closes #9643)

src/misc1.c

@@ -379,7 +379,7 @@ plines_win_nofill(
 
     lines = plines_win_nofold(wp, lnum);
     if (winheight > 0 && lines > wp->w_height)
-	return (int)wp->w_height;
+	return wp->w_height;
     return lines;
 }