perf: Use POLLIN instead of POLL_IN for perf poll data in flag

Currently we flag available data (via poll syscall) on perf fd with
POLL_IN macro, which is normally used for SIGIO interface.

We've been lucky, because POLLIN (0x1) is subset of POLL_IN (0x20001)
and sys_poll (do_pollfd function) cut the extra bit out (0x20000).
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1422467678-22341-1-git-send-email-jolsa@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/events/ring_buffer.c

@@ -13,12 +13,13 @@
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/circ_buf.h>
+#include <linux/poll.h>
 
 #include "internal.h"
 
 static void perf_output_wakeup(struct perf_output_handle *handle)
 {
-	atomic_set(&handle->rb->poll, POLL_IN);
+	atomic_set(&handle->rb->poll, POLLIN);
 
 	handle->event->pending_wakeup = 1;
 	irq_work_queue(&handle->event->pending);