kselftest/arm64: Fix typo in hwcap check

kselftest/arm64: Fix typo in hwcap check

We use a local variable hwcap to refer to the element of the hwcaps array
which we are currently checking. When checking for the relevant hwcap bit
being set in testing we were dereferencing hwcaps rather than hwcap in
fetching the AT_HWCAP to use, which is perfectly valid C but means we were
always checking the bit was set in the hwcap for whichever feature is first
in the array. Remove the stray s.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220907113400.12982-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>