drivers: phy: tweaks to phy_create()

If this was called with a NULL "dev" then it lead to a NULL dereference
when we called dev_WARN().  I have changed it to WARN_ON() so that we
get a stack dump and can fix the caller.

The rest of this patch is just cleanup like returning directly instead
of having do-nothing gotos.  Using descriptive labels instead of
GW-BASIC style "err0" and "err1".  I also flipped the order of
put_device() and ida_remove() so they are a mirror reflection of the
order they were allocated.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>