md: remove the 'super' sysfs attribute from devices in an 'md' array

Exposing the binary blob which is the md 'super-block' via sysfs doesn't
really fit with the whole sysfs model, and ever since commit
8118a859 ("sysfs: fix off-by-one error
in fill_read_buffer()") it doesn't actually work at all (as the size of
the blob is often one page).

(akpm: as in, fs/sysfs/file.c:fill_read_buffer() goes BUG)

So just remove it altogether.  It isn't really useful.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/md/md.c

@@ -1863,17 +1863,6 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 static struct rdev_sysfs_entry rdev_state =
 __ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
 
-static ssize_t
-super_show(mdk_rdev_t *rdev, char *page)
-{
-	if (rdev->sb_loaded && rdev->sb_size) {
-		memcpy(page, page_address(rdev->sb_page), rdev->sb_size);
-		return rdev->sb_size;
-	} else
-		return 0;
-}
-static struct rdev_sysfs_entry rdev_super = __ATTR_RO(super);
-
 static ssize_t
 errors_show(mdk_rdev_t *rdev, char *page)
 {
@@ -2060,7 +2049,6 @@ __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
 
 static struct attribute *rdev_default_attrs[] = {
 	&rdev_state.attr,
-	&rdev_super.attr,
 	&rdev_errors.attr,
 	&rdev_slot.attr,
 	&rdev_offset.attr,