Kernel: Use Userspace<T> for the chown syscall

Kernel/Process.h

@@ -285,7 +285,7 @@ public:
     int sys$umount(const char* mountpoint, size_t mountpoint_length);
     int sys$chmod(const char* pathname, size_t path_length, mode_t);
     int sys$fchmod(int fd, mode_t);
-    int sys$chown(const Syscall::SC_chown_params*);
+    int sys$chown(Userspace<const Syscall::SC_chown_params*>);
     int sys$fchown(int fd, uid_t, gid_t);
     int sys$socket(int domain, int type, int protocol);
     int sys$bind(int sockfd, const sockaddr* addr, socklen_t);

Kernel/Syscalls/chown.cpp

@@ -38,7 +38,7 @@ int Process::sys$fchown(int fd, uid_t uid, gid_t gid)
     return description->chown(uid, gid);
 }
 
-int Process::sys$chown(const Syscall::SC_chown_params* user_params)
+int Process::sys$chown(Userspace<const Syscall::SC_chown_params*> user_params)
 {
     REQUIRE_PROMISE(chown);
     Syscall::SC_chown_params params;