KVM: selftests: Fix kvm_check_cap() assertion

stable inclusion
from stable-5.10.47
commit 4658a8d3079137d8d407892bdc95b390a419c261
bugzilla: 172973 https://gitee.com/openeuler/kernel/issues/I4DAKB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4658a8d3079137d8d407892bdc95b390a419c261



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[ Upstream commit d8ac05ea ]

KVM_CHECK_EXTENSION ioctl can return any negative value on error,
and not necessarily -1. Change the assertion to reflect that.

Signed-off-by: Fuad Tabba <tabba@google.com>
Message-Id: <20210615150443.1183365-1-tabba@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>