Merge branch 'fix-asprintf-test-free' into 'master'

Add needed include for asprintf() test

See merge request redox-os/relibc!306

tests/stdio/printf.c

@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h> // free()
 #include <math.h> // INFINITY, NAN constants
 
 int main(void) {