alpha: copy_thread(): rename 'arg' argument to 'kthread_arg'

The 'arg' argument to copy_thread() is only ever used when forking a new
kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
with do_fork() and other arch-specific implementations of copy_thread()).
Signed-off-by: NAlex Dowad <alexinbeijing@gmail.com>
Signed-off-by: NMatt Turner <mattst88@gmail.com>

arch/alpha/kernel/process.c

@@ -236,12 +236,11 @@ release_thread(struct task_struct *dead_task)
 }
 
 /*
- * Copy an alpha thread..
+ * Copy architecture-specific thread state
  */
-
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	    unsigned long arg,
+	    unsigned long kthread_arg,
 	    struct task_struct *p)
 {
 	extern void ret_from_fork(void);
@@ -262,7 +261,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 			sizeof(struct switch_stack) + sizeof(struct pt_regs));
 		childstack->r26 = (unsigned long) ret_from_kernel_thread;
 		childstack->r9 = usp;	/* function */
-		childstack->r10 = arg;
+		childstack->r10 = kthread_arg;
 		childregs->hae = alpha_mv.hae_cache,
 		childti->pcb.usp = 0;
 		return 0;