[IA64] Fix broken sn2 build

Revert the change made to arch/ia64/sn/kernel/setup.c by commit
204fba4a as it breaks the build.

Fixing the build the b94b0808 way
breaks xpc because genksyms then fails to generate an CRC for
per_cpu____sn_cnodeid_to_nasid because of limitations in the
generic genksyms code.
Signed-off-by: Hedi Berriche <hedi@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/setup.c

@@ -71,7 +71,7 @@ EXPORT_SYMBOL(sn_rtc_cycles_per_second);
 DEFINE_PER_CPU(struct sn_hub_info_s, __sn_hub_info);
 EXPORT_PER_CPU_SYMBOL(__sn_hub_info);
 
-DEFINE_PER_CPU(short [MAX_COMPACT_NODES], __sn_cnodeid_to_nasid);
+DEFINE_PER_CPU(short, __sn_cnodeid_to_nasid[MAX_COMPACT_NODES]);
 EXPORT_PER_CPU_SYMBOL(__sn_cnodeid_to_nasid);
 
 DEFINE_PER_CPU(struct nodepda_s *, __sn_nodepda);