fix the following 'make includecheck' warning:
  kernel/trace/ring_buffer.c: trace.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <
1247068617.4382.107.camel@ht.satnam>
 }
 EXPORT_SYMBOL_GPL(tracing_is_on);
 
-#include "trace.h"
-
 #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array))
 #define RB_ALIGNMENT           4U
 #define RB_MAX_SMALL_DATA      (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)