perf build-id: Fix coding style, replace 8 spaces by tabs

Use tabs instead of 8 spaces for the indentation.
Signed-off-by: Martin Liška <mliska@suse.cz>
Link: http://lore.kernel.org/lkml/2983e2e0-6850-ad59-79d8-efe83b22cffe@suse.czSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>