LD_PRELOAD can load some additionals library. process_envvars() will add these lib into preloadlist.
preloadlist will be reused into dl_main(). A buffer list will be allocated with strdupa(). This buffer is not
freeED after strsep().
elf/rtld.c +1050 on 2.3.3.
I advise to free list just after the while & before HP_TIMING_NOW().
it's nothing (i know) :)
strdupa uses alloca.