Revert "tracing: Move event storage for array from macro to standalone function"

I originally wrote commit 35bb4399bd to shrink the size of the overhead of
tracepoints by several kilobytes. Later, I received a patch from Vaibhav
Nagarnaik that fixed a bug in the same code that this commit touches. Not
only did it fix a bug, it also removed code and shrunk the size of the
overhead of trace events even more than this commit did.

Since this commit is scheduled for 3.15 and Vaibhav's patch is already in
mainline, I need to revert this patch in order to keep it from conflicting
with Vaibhav's patch. Not to mention, Vaibhav's patch makes this patch
obsolete.

Link: http://lkml.kernel.org/r/20140320225637.0226041b@gandalf.local.home

Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/trace/ftrace.h

@@ -302,11 +302,15 @@ static struct trace_event_functions ftrace_event_type_funcs_##call = {	\
 #undef __array
 #define __array(type, item, len)					\
 	do {								\
+		mutex_lock(&event_storage_mutex);			\
 		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\
-		ret = ftrace_event_define_field(event_call, #type, len,	\
-				#item, offsetof(typeof(field), item),   \
-				sizeof(field.item),			\
-			 	is_signed_type(type), FILTER_OTHER); \
+		snprintf(event_storage, sizeof(event_storage),		\
+			 "%s[%d]", #type, len);				\
+		ret = trace_define_field(event_call, event_storage, #item, \
+				 offsetof(typeof(field), item),		\
+				 sizeof(field.item),			\
+				 is_signed_type(type), FILTER_OTHER);	\
+		mutex_unlock(&event_storage_mutex);			\
 		if (ret)						\
 			return ret;					\
 	} while (0);