[tip:perf/urgent] samples/bpf: Make perf_event_read() static

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  96c2fb69b92fcf6006dfb3017d6d887f8321407b
Gitweb:     http://git.kernel.org/tip/96c2fb69b92fcf6006dfb3017d6d887f8321407b
Author:     Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
AuthorDate: Thu, 15 Dec 2016 12:29:27 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 20 Dec 2016 09:37:33 -0300

samples/bpf: Make perf_event_read() static

While testing Joe's conversion of samples/bpf/ to use tools/lib/bpf/ I noticed
some warnings building samples/bpf/ on a Fedora Rawhide container, with
clang/llvm 3.9 I noticed this:

  [root@1e797fdfbf4f linux]# make -j4 O=/tmp/build/linux/ samples/bpf/
  make[1]: Entering directory '/tmp/build/linux'
    CHK     include/config/kernel.release
    GEN     ./Makefile
    CHK     include/generated/uapi/linux/version.h
    Using /git/linux as source for kernel
  <SNIP>
    HOSTCC  samples/bpf/trace_output_user.o
  /git/linux/samples/bpf/trace_output_user.c:64:6: warning: no previous
  prototype for 'perf_event_read' [-Wmissing-prototypes]
   void perf_event_read(print_fn fn)
        ^~~~~~~~~~~~~~~
    HOSTLD  samples/bpf/trace_output
  make[1]: Leaving directory '/tmp/build/linux'

Shut up the compiler by making that function static.

Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxx>
Cc: Joe Stringer <joe@xxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20161215152927.GC6866@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 samples/bpf/trace_output_user.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index 3bedd94..1a1da7b 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -61,7 +61,7 @@ struct perf_event_sample {
 	char data[];
 };
 
-void perf_event_read(print_fn fn)
+static void perf_event_read(print_fn fn)
 {
 	__u64 data_tail = header->data_tail;
 	__u64 data_head = header->data_head;