fix error returns in gethostby*_r functions

[musl] / src / network / getservbyport.c

#define _GNU_SOURCE
#include <netdb.h>

struct servent *getservbyport(int port, const char *prots)
{
        static struct servent se;
        static long buf[32/sizeof(long)];
        struct servent *res;
        if (getservbyport_r(port, prots, &se, (void *)buf, sizeof buf, &res))
                return 0;
        return &se;
}