Cleanup the usage of os::file_name_strcmp() in SharedPathsMiscInfo::check()

In SharedPathsMiscInfo::check(), os::file_name_strcmp() is called to compare the runtime path string with dump time path string. If the runtime path is longer than the dump time path, we need to copy the leading entries of the runtime path to a temporary string before the comparison. The length of the copied string is the same as the dump time path string. This operation is inefficient and could be error prone.