xen/multicalls: disable MC_DEBUG

It's useful - and probably should be a config - but its very heavyweight,
especially with the tracing stuff to help sort out problems.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index 7074c7e..3001162 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -30,7 +30,7 @@
 
 #define MC_BATCH	32
 
-#define MC_DEBUG	1
+#define MC_DEBUG	0
 
 #define MC_ARGS		(MC_BATCH * 16)
 
@@ -132,7 +132,7 @@
 	}
 
 	ret.mc = &b->entries[b->mcidx];
-#ifdef MC_DEBUG
+#if MC_DEBUG
 	b->caller[b->mcidx] = __builtin_return_address(0);
 #endif
 	b->mcidx++;