blockdev: Eliminate drive_del()

drive_del() has become a trivial wrapper around blk_unref().  Get rid
of it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/blockdev.c b/blockdev.c
index 63f797b..3038203 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -134,7 +134,7 @@
     DriveInfo *dinfo = blk_legacy_dinfo(blk);
 
     if (dinfo && dinfo->auto_del) {
-        drive_del(dinfo);
+        blk_unref(blk);
     }
 }
 
@@ -276,11 +276,6 @@
     error_printf(" %s", name);
 }
 
-void drive_del(DriveInfo *dinfo)
-{
-    blk_unref(dinfo->bdrv->blk);
-}
-
 typedef struct {
     QEMUBH *bh;
     BlockDriverState *bs;
@@ -1867,7 +1862,7 @@
         bdrv_set_on_error(bs, BLOCKDEV_ON_ERROR_REPORT,
                           BLOCKDEV_ON_ERROR_REPORT);
     } else {
-        drive_del(dinfo);
+        blk_unref(blk);
     }
 
     aio_context_release(aio_context);