Fix typo in static_calloc

Signed-off-by: Stefan Seefeld <stefan_seefeld@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fix: static_calloc should be thread-safe

Reported-by: Stefan Seefeld <stefan_seefeld@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>