Implement finit_module decoding

* bjm.c (module_init_flags): New xlat structure.
(sys_finit_module): New function.
* linux/dummy.h (sys_finit_module): Remove.
* linux/syscall.h (sys_finit_module): New prototype.
diff --git a/linux/syscall.h b/linux/syscall.h
index d8ce91f..17b9431 100644
--- a/linux/syscall.h
+++ b/linux/syscall.h
@@ -74,6 +74,7 @@
 int sys_fchownat();
 int sys_fcntl();
 int sys_fgetxattr();
+int sys_finit_module();
 int sys_flistxattr();
 int sys_flock();
 int sys_fork();