Fix the broken install

Fix the broken install

install -d /usr/share/doc/libva/html
install -m 0644 html-out/* /usr/share/doc/libva/html
install: omitting directory `html-out/search'
make[2]: *** [install-html-local] Error 1
make[2]: Leaving directory `/home/xhh/graphics/ex/vaapi/libva/doc'
make[1]: *** [install-am] Error 2
make[1]: Leaving directory `/home/xhh/graphics/ex/vaapi/libva/doc'
make: *** [install-recursive] Error 1

Signed-off-by: Xiang, Haihao <haihao.xiang@intel.com>
(cherry picked from commit ee948e105b97a03b60168b4e5aed3c64a14c37e6)