xcore: fix an warning of unused array when DIET mode is enable
diff --git a/arch/XCore/XCoreMapping.c b/arch/XCore/XCoreMapping.c
index e3a2abc..38494ef 100644
--- a/arch/XCore/XCoreMapping.c
+++ b/arch/XCore/XCoreMapping.c
@@ -1548,10 +1548,12 @@
 #endif
 }
 
+#ifndef CAPSTONE_DIET
 static name_map group_name_maps[] = {
 	{ XCORE_GRP_INVALID, NULL },
 	{ XCORE_GRP_JUMP, "jump" },
 };
+#endif
 
 const char *XCore_group_name(csh handle, unsigned int id)
 {