x86_64 ia32 ptrace: convert to compat_arch_ptrace

Now that there are no more special cases in sys32_ptrace, we
can convert to using the generic compat_sys_ptrace entry point.
The sys32_ptrace function gets simpler and becomes compat_arch_ptrace.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/ia32/ia32entry.S

@@ -430,7 +430,7 @@ ia32_sys_call_table:
 	.quad sys_setuid16
 	.quad sys_getuid16
 	.quad compat_sys_stime	/* stime */		/* 25 */
-	.quad sys32_ptrace	/* ptrace */
+	.quad compat_sys_ptrace	/* ptrace */
 	.quad sys_alarm
 	.quad sys_fstat	/* (old)fstat */
 	.quad sys_pause