[libxml2] Add uninstall target for examples

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 4e494b9ccb6af775108fdd7ac5bbd64c76047880
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Wed Aug 17 12:00:40 2022 +0200

    Add uninstall target for examples
    
    Fixes make distcheck.

 doc/examples/Makefile.am | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am
index 664e4e37..94a41401 100644
--- a/doc/examples/Makefile.am
+++ b/doc/examples/Makefile.am
@@ -15,6 +15,11 @@ install-data-local:
        $(MKDIR_P) $(DESTDIR)$(docdir)/examples
        -$(INSTALL) -m 0644 $(srcdir)/*.html $(srcdir)/*.c $(DESTDIR)$(docdir)/examples/
 
+uninstall-local:
+       rm -f $(DESTDIR)$(docdir)/examples/*.c
+       rm -f $(DESTDIR)$(docdir)/examples/*.html
+       -rmdir $(DESTDIR)$(docdir)/examples
+
 clean-local:
        test -f Makefile.am || rm -f test?.xml