tee: fix memory leak in tee_shm_register()

Moves the access_ok() check for valid memory range from user space from
the function tee_shm_register() to tee_ioctl_shm_register(). With this
we error out early before anything is done that must be undone on error.

Fixes: 578c3495 ("tee: add overflow check in register_shm_helper()")
Cc: stable@vger.kernel.org # 5.10
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>