patch 9.1.1132: Mark positions wrong after triggering multiline completion

Problem:  Mark positions wrong after triggering multiline completion.
Solution: Call deleted_lines_mark() after deleting lines.
          (zeertzjq)

closes: #16687

Co-authored-by: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/insexpand.c b/src/insexpand.c
index 624165a..dc8c76b 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -4429,6 +4429,7 @@
 		    VIM_CLEAR(remaining);
 		return;
 	    }
+	    deleted_lines_mark(curwin->w_cursor.lnum, 1L);
 	    curwin->w_cursor.lnum--;
 	}
 	// move cursor to end of line