[S390] Convert sys_clone to function with parameters.

Use function parameters instead of accessing the pt_regs structure
to get the parameters.
Also merge the 31 and 64 bit versions since they are identical.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 5a43f27..189d978 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -230,17 +230,11 @@
 	return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
 }
 
-SYSCALL_DEFINE0(clone)
+SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,
+		int __user *, parent_tidptr, int __user *, child_tidptr)
 {
 	struct pt_regs *regs = task_pt_regs(current);
-	unsigned long clone_flags;
-	unsigned long newsp;
-	int __user *parent_tidptr, *child_tidptr;
 
-	clone_flags = regs->gprs[3];
-	newsp = regs->orig_gpr2;
-	parent_tidptr = (int __user *) regs->gprs[4];
-	child_tidptr = (int __user *) regs->gprs[5];
 	if (!newsp)
 		newsp = regs->gprs[15];
 	return do_fork(clone_flags, newsp, regs, 0,