patch 8.0.1135: W_WINCOL() is always the same

Problem:    W_WINCOL() is always the same.
Solution:   Expand the macro.
diff --git a/src/gui_w32.c b/src/gui_w32.c
index d9ac846..aa09488 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -6608,7 +6608,7 @@
 	}
 	else if (curwin != NULL)
 	{
-	    p.x += TEXT_X(W_WINCOL(curwin) + curwin->w_wcol + 1);
+	    p.x += TEXT_X(curwin->w_wincol + curwin->w_wcol + 1);
 	    p.y += TEXT_Y(W_WINROW(curwin) + curwin->w_wrow + 1);
 	}
 	msg_scroll = FALSE;