version_policy.c: be less verbose at build time

Avoid generating build time noise so that real errors stand out.

https://en.wikipedia.org/wiki/Unix_philosophy

  Rule of Silence
  Developers should design programs so that they do not print
  unnecessary output. This rule aims to allow other programs
  and developers to pick out the information they need from a
  program's output without having to parse verbosity.

Test: Info messages no longer show up at build time.
Bug: 115998215
Change-Id: I33c18e2c7d77ed1bb4132debe13de2ae0907c34c

tools/version_policy.c

@@ -151,8 +151,8 @@ int main(int argc, char *argv[])
 		usage(argv[0]);
 	}
 
-	/* gimme all the details */
-	cil_set_log_level(CIL_INFO);
+	/* gimme only the important details */
+	cil_set_log_level(CIL_WARN);
 
 	/* read platform policy */
 	rc = read_cil_file(&base_db, base);