perf tools: Fix feature-bits rework fallout, remove unused variable

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
Link: http://lkml.kernel.org/n/tip-lfckuwbl8m1ykb7t9ydsxe4r@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

tools/perf/util/header.c

@@ -1415,15 +1415,12 @@ static int perf_header__adds_write(struct perf_header *header,
 				   struct perf_evlist *evlist, int fd)
 {
 	int nr_sections;
-	struct perf_session *session;
 	struct perf_file_section *feat_sec, *p;
 	int sec_size;
 	u64 sec_start;
 	int feat;
 	int err;
 
-	session = container_of(header, struct perf_session, header);
-
 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
 	if (!nr_sections)
 		return 0;