devres: fix devres_get()

Currently, devres_get() passes devres_free() the pointer to devres,
but devres_free() should be given with the pointer to resource data.

Fixes: 9ac7849e ("devres: device resource management")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable <stable@vger.kernel.org> # 2.6.21+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>