selftests/x86/ldt_gdt: remove unneeded semicolon

Eliminate the following coccicheck warning:
./tools/testing/selftests/x86/ldt_gdt.c:610:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>