bfq: Use 'ttime' local variable

Use local variable 'ttime' instead of dereferencing bfqq.
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bfq-iosched.c

@@ -5282,7 +5282,7 @@ static void bfq_update_io_thinktime(struct bfq_data *bfqd,
 
 	elapsed = min_t(u64, elapsed, 2ULL * bfqd->bfq_slice_idle);
 
-	ttime->ttime_samples = (7*bfqq->ttime.ttime_samples + 256) / 8;
+	ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8;
 	ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed,  8);
 	ttime->ttime_mean = div64_ul(ttime->ttime_total + 128,
 				     ttime->ttime_samples);