xen/arm: optee: fix possible memory leaks

xen/arm: optee: fix possible memory leaks

translate_noncontig() allocates domheap page for translated list
before calling to allocate_optee_shm_buf(), which can fail for number
of reason. Anyways, after fail we need to free the allocated page(s).

Another leak is possible if the same translate_noncontig() function
fails to get domain page. In this case it should free allocated
optee_shm_buf prior exit. This will also free allocated domheap page.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>