As the memory region is requested through request_mem_region
use the correct paired method to release it in the error path
and don't go "beneath the API".
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>