Revert "hwrng: virtio - ensure reads happen after successful probe"

Revert "hwrng: virtio - ensure reads happen after successful probe"

commit eeec626366ffe558fc3d5685bd2b49a962acf57d upstream.

This reverts commit e052dbf554610e2104c5a7518c4d8374bed701bb.

Now that we use the virtio ->scan() function to register with the hwrng
core, we will not get read requests till probe is successfully finished.

So revert the workaround we had in place to refuse read requests while
we were not yet setup completely.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>