patch 8.1.2228: screenpos() returns wrong values when 'number' is set

Problem:    screenpos() returns wrong values when 'number' is set. (Ben
            Jackson)
Solution:   Compare the column with the window width. (closes #5133)
diff --git a/src/move.c b/src/move.c
index 97f5ac1..d6b1c26 100644
--- a/src/move.c
+++ b/src/move.c
@@ -1217,7 +1217,7 @@
 	    col -= rowoff * width;
 	}
 	col -= wp->w_leftcol;
-	if (col >= width)
+	if (col >= wp->w_width)
 	    col = -1;
 	if (col >= 0)
 	    coloff = col - scol + wp->w_wincol + 1;