blk-iocost: tracing: atomic64_read(&ioc->vtime_rate) is assigned an extra semicolon

Remove extra semicolon.

Link: https://lkml.kernel.org/r/20220629030013.10362-1-kunyu@nfschina.com

Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Author: likunyur

include/trace/events/iocost.h

@@ -160,7 +160,7 @@ TRACE_EVENT(iocost_ioc_vrate_adj,
 
 	TP_fast_assign(
 		__assign_str(devname, ioc_name(ioc));
-		__entry->old_vrate = atomic64_read(&ioc->vtime_rate);;
+		__entry->old_vrate = atomic64_read(&ioc->vtime_rate);
 		__entry->new_vrate = new_vrate;
 		__entry->busy_level = ioc->busy_level;
 		__entry->read_missed_ppm = missed_ppm[READ];