ia64: remove the unused sn_coherency_id symbol

The sn_coherency_id symbol isn't used anywhere, remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20190813072514.23299-23-hch@lst.deSigned-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/uv/kernel/setup.c

@@ -16,9 +16,6 @@
 DEFINE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
 EXPORT_PER_CPU_SYMBOL_GPL(__uv_hub_info);
 
-long sn_coherency_id;
-EXPORT_SYMBOL_GPL(sn_coherency_id);
-
 struct redir_addr {
 	unsigned long redirect;
 	unsigned long alias;