Fix read_random_bytes yet again.

Sigh.

kernel.c

@@ -84,11 +84,10 @@ gettime(struct timeval *tv)
 /* If /dev/urandom doesn't exist, this will fail with ENOENT, which the
    caller will deal with gracefully. */
 
-ssize_t
-read_random_bytes(void *buf, size_t len)
+int
+read_random_bytes(void *buf, int len)
 {
-    int fd;
-    size_t rc;
+    int fd, rc;
 
     fd = open("/dev/urandom", O_RDONLY);
     if(fd < 0) {

kernel.h

@@ -77,6 +77,6 @@ int kernel_addresses(char *ifname, int ifindex, int ll,
                      struct kernel_route *routes, int maxroutes);
 int if_eui64(char *ifname, int ifindex, unsigned char *eui);
 int gettime(struct timeval *tv);
-ssize_t read_random_bytes(void *buf, size_t len);
+int read_random_bytes(void *buf, int len);
 int kernel_older_than(const char *sysname, int version, int sub_version);
 int kernel_has_ipv6_subtrees(void);