perf header: Remove data_offset seek as it's not needed

Removing data_offset seek as it's not needed, because data are not read
by syscall but mmaped instead.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1374083403-14591-3-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/header.c

@@ -2794,8 +2794,6 @@ int perf_session__read_header(struct perf_session *session)
 	perf_header__process_sections(header, fd, &session->pevent,
 				      perf_file_section__process);
 
-	lseek(fd, header->data_offset, SEEK_SET);
-
 	if (perf_evlist__prepare_tracepoint_events(session->evlist,
 						   session->pevent))
 		goto out_delete_evlist;