insert_resource() can fail when the resource added  overlaps
(partially or fully) with another.

Device tree and AMBA devices may contain resources that overlap, so they
could not call platform_device_add (see 02bbde78 ('Revert "of:
use platform_device_add"'))"

On the other hand, device trees are released using
platform_device_unregister(). This function calls platform_device_del(),
which calls release_resource(), that crashes when the resource has not
been added with with insert_resource. This was not an issue when the
device tree could not be modified online, but this is not the case
anymore.

This patch let the flow continue when there is an insert error, after
notifying the user with a dev_err(). r->parent is set to NULL, so
platform_device_del() knows that the resource was not added, and
therefore it should not be released.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>