talk: Make talk_fullpath() do the right thing when voicing a directory

The component after the final '/' can be a directory, so don't
unconditionally treat it as a file.

Also check to make sure there is something after the final '/' otherwise
we end up voicing it as '//'

Change-Id: I56d69ea3f299e524df29c328ec9eeb3cfc22ff42

apps/talk.c

@@ -1232,8 +1232,18 @@ int talk_fullpath(const char* path, bool enqueue)
         ptr = strchr(start, PATH_SEPCH);
     }
 
-    /* no more slashes, final component is a filename */
+    /* no more slashes, figure out final component */
+    if (!*start) {
+        return 1;
+    }
+
+    DIR* dir = opendir(buf);
+    if (dir) {
+        closedir(dir);
+        return talk_dir_or_spell(buf, NULL, true);
+    } else {
         return talk_file_or_spell(NULL, buf, NULL, true);
+    }
 }
 
 /* say a numeric value, this word ordering works for english,