UPSTREAM: linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_check

We must not use the pointer output without validating the
success of the random read.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-7-broonie@kernel.org


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
(cherry picked from commit 904caa6413c87aacbf7d0682da617c39ca18cf1a)
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 148665638
Change-Id: I534dcbca40afa3d75a7ddbc6e81f13361fb6e031