virtio_blk: mark virtio_blk with __refdata to kill spurious section mismatch

The variable virtio_blk references the function virtblk_probe() (which
is in .devinit section) and also references the function
virtblk_remove() ( which is in .devexit section). So, virtio_blk
simultaneously refers .devinit and .devexit section. To avoid this
messup, we mark virtio_blk as __refdata.

We were warned by the following warning:

  LD      drivers/block/built-in.o
  WARNING: drivers/block/built-in.o(.data+0xc8dc): Section mismatch in
  reference from the variable virtio_blk to the function
  .devinit.text:virtblk_probe()
  The variable virtio_blk references
  the function __devinit virtblk_probe()
  If the reference is valid then annotate the
  variable with __init* or __refdata (see linux/init.h) or name the variable:
  *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

  WARNING: drivers/block/built-in.o(.data+0xc8e0): Section mismatch in
  reference from the variable virtio_blk to the function
  .devexit.text:virtblk_remove()
  The variable virtio_blk references
  the function __devexit virtblk_remove()
  If the reference is valid then annotate the
  variable with __exit* (see linux/init.h) or name the variable:
  *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/block/virtio_blk.c

@@ -424,7 +424,12 @@ static unsigned int features[] = {
 	VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_IDENTIFY
 };
 
-static struct virtio_driver virtio_blk = {
+/*
+ * virtio_blk causes spurious section mismatch warning by
+ * simultaneously referring to a __devinit and a __devexit function.
+ * Use __refdata to avoid this warning.
+ */
+static struct virtio_driver __refdata virtio_blk = {
 	.feature_table = features,
 	.feature_table_size = ARRAY_SIZE(features),
 	.driver.name =	KBUILD_MODNAME,