Correctly format debug message in GetLogName

The previous iteration would print out that the new logfile was being
created at fbs_log-1 without adding the correct padding.

Change-Id: I2a93bf8b3dc0a5a6c3e82924d40849af0bb836dc
Signed-off-by: James Kuszmaul <jabukuszmaul+collab@gmail.com>
diff --git a/aos/logging/log_namer.cc b/aos/logging/log_namer.cc
index c1dd30a..77312fe 100644
--- a/aos/logging/log_namer.cc
+++ b/aos/logging/log_namer.cc
@@ -68,11 +68,9 @@
   if (asprintf(filename, "%s/%s-%03d", directory, basename, fileindex) == -1) {
     PLOG(FATAL) << "couldn't create final name";
   }
-  LOG(INFO) << "Created log file (" << basename << "-" << fileindex
-            << ") in directory (" << directory
-            << "). Previous file "
-               "was ("
-            << previous << ").";
+  // Fix basename formatting.
+  LOG(INFO) << "Created log file (" << filename << "). Previous file was ("
+            << directory << "/" << previous << ").";
 }
 
 bool FoundThumbDrive(const char *path) {