kselftest/arm64: Remove unused parameters in abi test

Remove unused parameter i in tpidr2.c main function.

Signed-off-by: xieming <xieming@kylinos.cn>
Link: https://lore.kernel.org/r/20240422015730.89805-1-xieming@kylinos.cn


Signed-off-by: Will Deacon <will@kernel.org>