patch 8.2.4241: some type casts are redundant

Problem:    Some type casts are redundant.
Solution:   Remove the type casts. (closes #9643)
diff --git a/src/drawscreen.c b/src/drawscreen.c
index d03c429..5732b89 100644
--- a/src/drawscreen.c
+++ b/src/drawscreen.c
@@ -538,7 +538,7 @@
 			this_ru_col + wp->w_wincol, fillchar, fillchar, attr);
 
 	if (get_keymap_str(wp, (char_u *)"<%s>", NameBuff, MAXPATHL)
-		&& (int)(this_ru_col - len) > (int)(STRLEN(NameBuff) + 1))
+		&& (this_ru_col - len) > (int)(STRLEN(NameBuff) + 1))
 	    screen_puts(NameBuff, row, (int)(this_ru_col - STRLEN(NameBuff)
 						   - 1 + wp->w_wincol), attr);
 
@@ -797,7 +797,7 @@
 	i = redraw_cmdline;
 	screen_fill(row, row + 1,
 		this_ru_col + off + (int)STRLEN(buffer),
-		(int)(off + width),
+		(off + width),
 		fillchar, fillchar, attr);
 	// don't redraw the cmdline because of showing the ruler
 	redraw_cmdline = i;
@@ -1038,8 +1038,7 @@
     }
     wp->w_winbar_items[item_idx].wb_menu = NULL; // end marker
 
-    screen_line(wp->w_winrow, wp->w_wincol, (int)wp->w_width,
-							  (int)wp->w_width, 0);
+    screen_line(wp->w_winrow, wp->w_wincol, wp->w_width, wp->w_width, 0);
 }
 #endif
 
@@ -1372,8 +1371,7 @@
     }
 #endif
 
-    screen_line(row + W_WINROW(wp), wp->w_wincol, (int)wp->w_width,
-						     (int)wp->w_width, 0);
+    screen_line(row + W_WINROW(wp), wp->w_wincol, wp->w_width, wp->w_width, 0);
 
     // Update w_cline_height and w_cline_folded if the cursor line was
     // updated (saves a call to plines() later).