blk_mq: remove repeated includes

Remove a repeated "#include<linux/sched/sysctl.h>".
Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20211123063340.25882-1-guozhengkui@vivo.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

@@ -28,7 +28,6 @@
 #include <linux/crash_dump.h>
 #include <linux/prefetch.h>
 #include <linux/blk-crypto.h>
-#include <linux/sched/sysctl.h>
 
 #include <trace/events/block.h>