sh: Fix kGDB NMI handling.

in_nmi shifted down a few labels, so we were inadvertently
clearing the lower byte of do_syscall_trace, badness ensues.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/kernel/entry.S

@@ -644,7 +644,7 @@ skip_restore:
 	!
 #if defined(CONFIG_KGDB_NMI)
 	! Clear in_nmi
-	mov.l	4f, k0
+	mov.l	6f, k0
 	mov	#0, k1
 	mov.b	k1, @k0
 #endif