fix assorted unused code and wrong format specs found by cppchekc (bug 6716)

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/e2fsprogs/old_e2fsprogs/blkid/cache.c b/e2fsprogs/old_e2fsprogs/blkid/cache.c
index d1d2914..251e499 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/cache.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/cache.c
@@ -115,7 +115,7 @@
 			argv[0], ret);
 		exit(1);
 	}
-	if ((ret = blkid_probe_all(cache) < 0))
+	if ((ret = blkid_probe_all(cache)) < 0)
 		fprintf(stderr, "error probing devices\n");
 
 	blkid_put_cache(cache);