commit f78d4ed7 has fixed qemu tag, making 'sample-pages' option tag
involved by accident, which introduced since 6.1 in commit 7afa08cd.
revert this line.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>