MIPS: Lasat: Remove unused function from sysctl code.

Remove the function proc_dolasatint() 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>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8868/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>