block: Make ioprio_best() static

Nobody outside of block/ioprio.c uses it.

Reviewed-by: Damien Le Moal <[e-mail]>
Tested-by: Damien Le Moal <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jens Axboe <[e-mail]>

block/ioprio.c

···
 	return ret;
 }
 
-int ioprio_best(unsigned short aprio, unsigned short bprio)
+static int ioprio_best(unsigned short aprio, unsigned short bprio)
 {
 	if (!ioprio_valid(aprio))
 		aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM);

include/linux/ioprio.h

···
 	return __get_task_ioprio(current);
 }
 
-/*
- * For inheritance, return the highest of the two given priorities
- */
-extern int ioprio_best(unsigned short aprio, unsigned short bprio);
-
 extern int set_task_ioprio(struct task_struct *task, int ioprio);
 
 #ifdef CONFIG_BLOCK