sh: Fix in_nmi symbol build error.

If CONFIG_KGDB_NMI is disabled, we're left with a stray in_nmi
reference that can't be resolved. Move the symbol under the ifdef,
too.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S
index 659cc08..b0b59d4 100644
--- a/arch/sh/kernel/cpu/sh3/entry.S
+++ b/arch/sh/kernel/cpu/sh3/entry.S
@@ -320,7 +320,9 @@
 
 	.align	2
 5:	.long	0x00001000	! DSP
+#ifdef CONFIG_KGDB_NMI
 6:	.long	in_nmi
+#endif
 7:	.long	0x30000000
 
 ! common exception handler