x86/platform/UV/NMI: Fix uneccessary kABI breakage

The addition of support for UV Hubless systems unneccessarily broke
the kABI for a symbol that is not used by external kernel modules.
Remove the symbol from the EXPORT list.

Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Russ Anderson <russ.anderson@hpe.com>
Link: http://lkml.kernel.org/r/20170215001129.068078379@asylum.americas.sgi.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/platform/uv/uv_nmi.c

@@ -65,7 +65,6 @@
 static struct uv_hub_nmi_s **uv_hub_nmi_list;
 
 DEFINE_PER_CPU(struct uv_cpu_nmi_s, uv_cpu_nmi);
-EXPORT_PER_CPU_SYMBOL_GPL(uv_cpu_nmi);
 
 /* UV hubless values */
 #define NMI_CONTROL_PORT	0x70