[PATCH] unify sys_ptrace prototype

Make sure we always return, as all syscalls should.  Also move the common
prototype to <linux/syscalls.h>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/ptrace.c

@@ -354,7 +354,7 @@ ptrace_set_thread_area(struct task_struct *child,
 	return 0;
 }
 
-asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
+asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
 {
 	struct task_struct *child;
 	struct user * dummy = NULL;