uapi: convert u64 to __u64 in exported headers

The u64 type is not defined in any exported kernel headers, so trying to
use it will lead to build failures.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index e244ed4..853bc1c 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -788,7 +788,7 @@
 #define PERF_MEM_TLB_SHIFT	26
 
 #define PERF_MEM_S(a, s) \
-	(((u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
+	(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
 
 /*
  * single taken branch record layout: