patch 9.1.0294: Text height function does not respect it's argument

Problem:  plines_m_win() does not take into account it's "limit_winheight"
          argument for filler lines below the last line of the buffer.
          (after v9.1.0280)
Solution: Check window height when "limit_winheight" is TRUE.
          (Luuk van Baal)

closes: #14449

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/popupwin.c b/src/popupwin.c
index bdf4ac7..25bb153 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -654,7 +654,7 @@
 	    wp->w_topline = wp->w_buffer->b_ml.ml_line_count;
 	while (wp->w_topline < wp->w_cursor.lnum
 		&& wp->w_topline < wp->w_buffer->b_ml.ml_line_count
-		&& plines_m_win(wp, wp->w_topline, wp->w_cursor.lnum, TRUE)
+		&& plines_m_win(wp, wp->w_topline, wp->w_cursor.lnum, FALSE)
 								> wp->w_height)
 	    ++wp->w_topline;
     }