Revert "ll_rw_blk: temporarily enable max_segments tweaking"

This was a temporary debugging thing for sg chaining testing, revert
it now as it has served its purpose.

This reverts commit 563063a.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/ll_rw_blk.c

@@ -4080,23 +4080,7 @@ static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 	return queue_var_show(max_hw_sectors_kb, (page));
 }
 
-static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
-{
-	return queue_var_show(q->max_phys_segments, page);
-}
-
-static ssize_t queue_max_segments_store(struct request_queue *q,
-					const char *page, size_t count)
-{
-	unsigned long segments;
-	ssize_t ret = queue_var_store(&segments, page, count);
 
-	spin_lock_irq(q->queue_lock);
-	q->max_phys_segments = segments;
-	spin_unlock_irq(q->queue_lock);
-
-	return ret;
-}
 static struct queue_sysfs_entry queue_requests_entry = {
 	.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
 	.show = queue_requests_show,
@@ -4120,12 +4104,6 @@ static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
 	.show = queue_max_hw_sectors_show,
 };
 
-static struct queue_sysfs_entry queue_max_segments_entry = {
-	.attr = {.name = "max_segments", .mode = S_IRUGO | S_IWUSR },
-	.show = queue_max_segments_show,
-	.store = queue_max_segments_store,
-};
-
 static struct queue_sysfs_entry queue_iosched_entry = {
 	.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
 	.show = elv_iosched_show,
@@ -4137,7 +4115,6 @@ static struct attribute *default_attrs[] = {
 	&queue_ra_entry.attr,
 	&queue_max_hw_sectors_entry.attr,
 	&queue_max_sectors_entry.attr,
-	&queue_max_segments_entry.attr,
 	&queue_iosched_entry.attr,
 	NULL,
 };