parasite: simplify syscall check

In is_required_syscall() req_sysnr is set according to the native mode
so we can check the syscall number directly against it.

No functional change expected.

Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/parasite-syscall.c

@@ -1049,12 +1049,8 @@ static inline int is_required_syscall(user_regs_struct_t *regs, pid_t pid,
 
 	pr_debug("%d (%s) is going to execute the syscall %lu, required is %d\n",
 		pid, mode, REG_SYSCALL_NR(*regs), req_sysnr);
-	if (user_regs_native(regs) && (REG_SYSCALL_NR(*regs) == sys_nr))
-		return true;
-	if (!user_regs_native(regs) && (REG_SYSCALL_NR(*regs) == sys_nr_compat))
-		return true;
 
-	return false;
+	return (REG_SYSCALL_NR(*regs) == req_sysnr);
 }
 /*
  * Trap tasks on the exit from the specified syscall