persistent_ram_new() returns ERR_PTR() value on errors, so during
freeing of the przs we should check for both NULL and IS_ERR() entries,
otherwise bad things will happen.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>