tracing: Fix sign fields in ftrace_define_fields_##call()

Add is_signed_type() call to trace_define_field() in ftrace macros.

The code previously just passed in 0 (false), disregarding whether
or not the field was actually a signed type.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D3A.6020007@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 458e5bf..d4fa5dc 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -158,7 +158,8 @@
 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
 				 offsetof(typeof(field), item),		\
-				 sizeof(field.item), 0, FILTER_OTHER);	\
+				 sizeof(field.item),			\
+				 is_signed_type(type), FILTER_OTHER);	\
 	if (ret)							\
 		return ret;
 
@@ -168,8 +169,8 @@
 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
 				 offsetof(typeof(field),		\
 					  container.item),		\
-				 sizeof(field.container.item), 0,	\
-				 FILTER_OTHER);				\
+				 sizeof(field.container.item),		\
+				 is_signed_type(type), FILTER_OTHER);	\
 	if (ret)							\
 		return ret;