patch 8.1.2086: missing a few changes for the renamed files

Problem:    Missing a few changes for the renamed files.
Solution:   Rename in a few more places. (Ken Takata)
diff --git a/src/proto/popupmenu.pro b/src/proto/popupmenu.pro
index c019663..f5b6c0c 100644
--- a/src/proto/popupmenu.pro
+++ b/src/proto/popupmenu.pro
@@ -1,4 +1,4 @@
-/* popupmnu.c */
+/* popupmenu.c */
 void pum_display(pumitem_T *array, int size, int selected);
 void pum_call_update_screen(void);
 int pum_under_menu(int row, int col);