staging: iio: accel: sca3000_core.c: Remove unused function

Remove the function sca3000_check_status() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>