[ Upstream commit d1d2c290b3c04b65fa6132eeebe50a070746d8f6 ]

The platform_get_resource() function doesn't return error pointers, it
returns NULL on error.

Fixes: 3d4e5184 ("thermal: armada: convert driver to syscon register accesses")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NMiquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>