Remove wholedisk check from vdev_disk_open()

As described by the comment and enforced the by assertion the
v->vdev_wholedisk will never be -1.  The wholedisk handling
is performed by the user space utilities.  To prevent confusion
this dead code is being removed.

Signed-off-by: Brian Behlendorf <[email protected]>

module/zfs/vdev_disk.c

@@ -294,20 +294,6 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 	/*  Determine the physical block size */
 	block_size = vdev_bdev_block_size(vd->vd_bdev);
 
-	/* We think the wholedisk property should always be set when this
-	 * function is called.  ASSERT here so if any legitimate cases exist
-	 * where it's not set, we'll find them during debugging.  If we never
-	 * hit the ASSERT, this and the following conditional statement can be
-	 * removed. */
-	ASSERT3S(v->vdev_wholedisk, !=, -1ULL);
-
-	/* The wholedisk property was initialized to -1 in vdev_alloc() if it
-	 * was unspecified.  In that case, check if this is a whole device.
-	 * When bdev->bd_contains == bdev we have a whole device and not simply
-	 * a partition. */
-	if (v->vdev_wholedisk == -1ULL)
-		v->vdev_wholedisk = (bdev->bd_contains == bdev);
-
 	/* Clear the nowritecache bit, causes vdev_reopen() to try again. */
 	v->vdev_nowritecache = B_FALSE;