fix regression/typo that disabled __simple_malloc when calloc is used
fix regression/typo that disabled __simple_malloc when calloc is used

commit ba819787ee93ceae94efd274f7849e317c1bff58 introduced this
regression. since the __malloc0 weak alias was not properly provided
by __simple_malloc, use of calloc forced the full malloc to be linked.

chardi/musl,chardi/musl,chardi/musl