codec: dmo: avoid null-pointer dereference.
codec: dmo: avoid null-pointer dereference.

Check the return value of malloc to avoid a null-pointer dereference.

Signed-off-by: Jean-Baptiste Kempf <7b85a41a628204b76aba4326273a3ccc74bd009a@videolan.org>
(cherry picked from commit 229c385a79d48e41687fae8b4dfeaeef9c8c3eb7)
Signed-off-by: Jean-Baptiste Kempf <7b85a41a628204b76aba4326273a3ccc74bd009a@videolan.org>

vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1,jomanmuk/vlc-2.1,jomanmuk/vlc-2.1,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1,jomanmuk/vlc-2.1,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1