blktrace: fix t_error()

Impact: fix error flag output

t_error() should return t->error but not t->sector.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <49C8945F.5020802@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/blktrace.c

@@ -968,7 +968,7 @@ static inline unsigned long long t_sector(const struct trace_entry *ent)
 
 static inline __u16 t_error(const struct trace_entry *ent)
 {
-	return te_blk_io_trace(ent)->sector;
+	return te_blk_io_trace(ent)->error;
 }
 
 static __u64 get_pdu_int(const struct trace_entry *ent)