perf tools: Add compress.h for the *_decompress_to_file() headers

Out of util.h, the implementations were already in separate files, that
are built conditionally.

Link: http://lkml.kernel.org/n/tip-0ur7szxsb59f8758kfe63prb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index cbfe17f..3339ab7 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -3,6 +3,7 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <errno.h>
+#include "compress.h"
 #include "path.h"
 #include "symbol.h"
 #include "dso.h"