perf evlist: Introduce 'disable' method

To remove the last case of access to the FD() macro outside the library.

Inspired by a patch by Borislav that moved the FD() macro to util.h, for
namespace concerns I rather preferred to constrain it to ev{sel,list}.c.

Cc: Borislav Petkov <bp@amd64.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qn893qsstcg366tkucu649qj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index b2b8623..ce85ae9 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -53,6 +53,8 @@
 int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite);
 void perf_evlist__munmap(struct perf_evlist *evlist);
 
+void perf_evlist__disable(struct perf_evlist *evlist);
+
 static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
 					 struct cpu_map *cpus,
 					 struct thread_map *threads)