Initialize phtread_attr_t structure

FreeBSD 10.0 man page for pthread_attr_get_np(3) highly recommends to initialize the structure before calling the function. Indeed, without initialization, Chromium Content Framework (cef) based on 35.0.1916.27 crashes.
 
http://www.freebsd.org/cgi/man.cgi?query=pthread_attr_get_np