If 'devm_kstrdup()' fails, we should return -ENOMEM.

While at it, move the 'of_node_put()' call in the error handling path and
after the 'machine' has been copied.
Better safe than sorry.

Fixes: a6fc3b69 ("soc: fsl: add GUTS driver for QorIQ platforms")
Depends-on: fddacc7ff4dd ("soc: fsl: guts: Revert commit 3c0d64e8")
Suggested-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Li Yang <leoyang.li@nxp.com>