h8300: switch to kernel_clone()

The old _do_fork() helper is removed in favor of the new kernel_clone() helper.
The latter adheres to naming conventions for kernel internal syscall helpers.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
Link: https://lore.kernel.org/r/20200819104655.436656-3-christian.brauner@ubuntu.com

arch/h8300/kernel/process.c

@@ -172,5 +172,5 @@ asmlinkage int sys_clone(unsigned long __user *args)
 	kargs.exit_signal	= (lower_32_bits(clone_flags) & CSIGNAL);
 	kargs.stack		= newsp;
 
-	return _do_fork(&kargs);
+	return kernel_clone(&kargs);
 }