stream_filter/record.c: Read() return 0 on malloc failure.

If no memory could be allocated, then return 0 in Read() for this stream_filter.
VLC core will then neatly handle this error situation. Otherwise a buffer overflow
is triggered.

modules/stream_filter/record.c

@@ -121,6 +121,9 @@ static int Read( stream_t *s, void *p_read, unsigned int i_read )
     if( p_sys->f && !p_record )
         p_record = malloc( i_read );
 
+    if (!p_record)
+        return 0; /* VLC_ENOMEM */
+
     /* */
     const int i_record = stream_Read( s->p_source, p_record, i_read );