Switch to PTHREAD_MUTEX_ERRORCHECK mutexen.
Switch to PTHREAD_MUTEX_ERRORCHECK mutexen.

This is very unlikely to make any difference, but the sheer stupidity
fot he PTHREAD_MUTEX_NORMAL definition is ubearable, now that I've
become aware of it.

Inspired by: CERT secure coding POS04-C

zhoualbeart/Varnish-Cache,gauthier-delacroix/Varnish-Cache,varnish/Varnish-Cache,zhoualbeart/Varnish-Cache,gquintard/Varnish-Cache,varnish/Varnish-Cache,franciscovg/Varnish-Cache,gquintard/Varnish-Cache,gauthier-delacroix/Varnish-Cache,mrhmouse/Varnish-Cache,mrhmouse/Varnish-Cache,mrhmouse/Varnish-Cache,feld/Varnish-Cache,zhoualbeart/Varnish-Cache,chrismoulton/Varnish-Cache,feld/Varnish-Cache,varnish/Varnish-Cache,gauthier-delacroix/Varnish-Cache,feld/Varnish-Cache,franciscovg/Varnish-Cache,chrismoulton/Varnish-Cache,varnish/Varnish-Cache,zhoualbeart/Varnish-Cache,chrismoulton/Varnish-Cache,gquintard/Varnish-Cache,zhoualbeart/Varnish-Cache,gauthier-delacroix/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,feld/Varnish-Cache,mrhmouse/Varnish-Cache,ajasty-cavium/Varnish-Cache,ajasty-cavium/Varnish-Cache,varnish/Varnish-Cache,chrismoulton/Varnish-Cache,ajasty-cavium/Varnish-Cache,chrismoulton/Varnish-Cache,gauthier-delacroix/Varnish-Cache,franciscovg/Varnish-Cache,franciscovg/Varnish-Cache,franciscovg/Varnish-Cache,ajasty-cavium/Varnish-Cache,mrhmouse/Varnish-Cache,ajasty-cavium/Varnish-Cache