vorbis: Avoid some out-of-bounds reads

Fixes Bug: #190
Chromium Bug: #100543
Related to CVE-2011-3893

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 57cd6d709565e84e84385f8f2a9641ca3fa718be)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 4a94678f1be4b7d47f862e9523ca3358255da5d4)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 6d6254ba9fbb22260939c06db1faed5bbd295ad4)

Conflicts:

	libavcodec/vorbis.c
1 file changed