linuxthreads.old: fix typo in pthread_mutex_unlock hidden prototype
linuxthreads.old: fix typo in pthread_mutex_unlock hidden prototype

Reported-by: Tony Wu <38d699a2ec8283e63ba2d5893eaaac3c6cd66428@gmail.com>
Signed-off-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@gentoo.org>

ndmsystems/uClibc,ndmsystems/uClibc,ndmsystems/uClibc,ndmsystems/uClibc