[IA64] change sh_change_coherence oemcall to use nolock

Change sn_change_coherence's ia64_sal_oemcall to the nolock variety since
PROM does the locking for this function internally.
Signed-off-by: NDean Nelson <dcn@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

include/asm-ia64/sn/sn_sal.h

@@ -696,8 +696,8 @@ static inline int
 sn_change_coherence(u64 *new_domain, u64 *old_domain)
 {
 	struct ia64_sal_retval ret_stuff;
-	ia64_sal_oemcall(&ret_stuff, SN_SAL_COHERENCE, (u64)new_domain,
-			 (u64)old_domain, 0, 0, 0, 0, 0);
+	ia64_sal_oemcall_nolock(&ret_stuff, SN_SAL_COHERENCE, (u64)new_domain,
+				(u64)old_domain, 0, 0, 0, 0, 0);
 	return ret_stuff.status;
 }