KEYS: Include linux/errno.h in linux/verification.h

KEYS: Include linux/errno.h in linux/verification.h

[ Upstream commit 0a596b0682a7ce37e26c36629816f105c6459d06 ]

Add inclusion of linux/errno.h as otherwise the reference to EINVAL
may be invalid.

Fixes: f3cf4134c5c6 ("bpf: Add bpf_lookup_*_key() and bpf_key_put() kfuncs")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308261414.HKw1Mrip-lkp@intel.com/
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>