Use a simpler rounding up method for calculating the number of rows to reserve

Author: hamishcoleman

src/oping.c

@@ -1292,9 +1292,8 @@ static int on_resize (pingobj_t *ping) /* {{{ */
 	if ((height < 1) || (width < 1))
 		return (EINVAL);
 
-        int box_rows_count = host_num / opt_columns;
-        if (box_rows_count < 1)
-            box_rows_count = 1;
+        /* calculate the number of box rows, rounding up */
+        int box_rows_count = (host_num+opt_columns-1) / opt_columns;
 
 	main_win_height = height - (box_height * box_rows_count);
 	wresize (main_win, main_win_height, /* width = */ width);
@@ -1385,9 +1384,8 @@ static int pre_loop_hook (pingobj_t *ping) /* {{{ */
 		init_pair (OPING_RED_HIST,    COLOR_RED,    COLOR_YELLOW);
 	}
 
-        int box_rows_count = host_num / opt_columns;
-        if (box_rows_count < 1)
-            box_rows_count = 1;
+        /* calculate the number of box rows, rounding up */
+        int box_rows_count = (host_num+opt_columns-1) / opt_columns;
 
 	main_win_height = height - (box_height * box_rows_count);
 	main_win = newwin (/* height = */ main_win_height,