Added note about strtok() not being thread safe

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@478 a1c6a512-1295-4272-9138-f99709370657

firmware/common/dir.c

@@ -48,6 +48,7 @@ DIR* opendir(char* name)
         return NULL;
     }
 
+    /* fixme: strtok() is not thread safe, and fat_getnext() calls yield() */
     for ( part = strtok(name, "/"); part;
           part = strtok(NULL, "/") ) {
         int partlen = strlen(part);