syscall_steal: rename sys_call_table to fix compile error

syscall_steal: rename sys_call_table to fix compile error

sys_call_table is already declared in arch/x86/include/asm/syscall.h but of
cource not exported by the kernel.
before this commit, gcc complains as follows:
/usr/src/linux-headers-6.1.0-16-common/arch/x86/include/asm/syscall.h:21:29:
note: previous declaration of 'sys_call_table' with type 'long int (*
const[])(const struct pt_regs *)'
   21 | extern const sys_call_ptr_t sys_call_table[];