Fix log message saying what fraction of paths we can likely build

When trying to get Shadow working with Tor master, Rob and I came across this strange log message:

[notice] I learned some more directory information, but not enough to build a circuit: We need more microdescriptors: we have 5/5, and can only build 020274120f likely paths. (We have 05001111756f guards bw, 1005016602000f midpoint bw, and 013634243140f exit bw.)

I tried various things, but didn't find out how to fix this. Here's a workaround that may help track down the bug:

diff --git a/src/or/nodelist.c b/src/or/nodelist.c
index 178f084..d566fd9 100644
--- a/src/or/nodelist.c
+++ b/src/or/nodelist.c
@@ -1373,9 +1373,9 @@ compute_frac_paths_available(const networkstatus_t *consensus,
     f_exit = f_myexit;
 
   tor_asprintf(status_out,
-               "%d%% of guards bw, "
-               "%d%% of midpoint bw, and "
-               "%d%% of exit bw",
+               "%d percent of guards bw, "
+               "%d percent of midpoint bw, and "
+               "%d percent of exit bw",
                (int)(f_guard*100),
                (int)(f_mid*100),
                (int)(f_exit*100));
@@ -1471,7 +1471,7 @@ update_router_have_minimum_dir_info(void)
     if (paths < get_frac_paths_needed_for_circs(options,consensus)) {
       tor_snprintf(dir_info_status, sizeof(dir_info_status),
                    "We need more %sdescriptors: we have %d/%d, and "
-                   "can only build %d%% of likely paths. (We have %s.)",
+                   "can only build %d percent of likely paths. (We have %s.)",
                    using_md?"micro":"", num_present, num_usable,
                    (int)(paths*100), status);
       /* log_notice(LD_NET, "%s", dir_info_status); */

Output is now:

[notice] I learned some more directory information, but not enough to build a circuit: We need more descriptors: we have 4/5, and can only build 46 percent of likely paths. (We have 55 percent of guards bw, 84 percent of midpoint bw, and 100 percent of exit bw.)