hapdec: remove unused memory.h include

Most systems have this, so it isn't really a problem to include it
even if it's not used, but some do not have memory.h as it is
non-standard. Since it's unused just remove it anyway.

libavcodec/hapdec.c

@@ -37,7 +37,6 @@
 #include "bytestream.h"
 #include "hap.h"
 #include "internal.h"
-#include "memory.h"
 #include "snappy.h"
 #include "texturedsp.h"
 #include "thread.h"