stream: Fix segfault caused by invalid seek

Sample can be found on https://www.dropbox.com/s/cd56gjk4ablimp5/A_lawnmower.wmv
md5: d87c039c304b41cc30bddfe21e88af36

src/input/stream.c

@@ -1260,7 +1260,7 @@ static int AStreamSeekStream( stream_t *s, uint64_t i_pos )
         if( p_sys->stream.i_used < STREAM_READ_ATONCE / 2 )
             p_sys->stream.i_used = STREAM_READ_ATONCE / 2;
 
-        if( AStreamRefillStream( s ) && i_pos == tk->i_end )
+        if( AStreamRefillStream( s ) && i_pos >= tk->i_end )
             return VLC_EGENERIC;
     }
     return VLC_SUCCESS;