Add fio_socklen_t

HPUX decides to be different yet again, add an OS typedef
to handle this instead of ifdefs in the code.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/server.c b/server.c
index 37ba593..07f3216 100644
--- a/server.c
+++ b/server.c
@@ -400,7 +400,7 @@
 static int accept_loop(int listen_sk)
 {
 	struct sockaddr_in addr;
-	socklen_t len = sizeof(addr);
+	fio_socklen_t len = sizeof(addr);
 	struct pollfd pfd;
 	int ret, sk, flags, exitval = 0;
 
@@ -631,7 +631,7 @@
 {
 	struct sockaddr_in saddr_in;
 	struct sockaddr addr;
-	socklen_t len;
+	fio_socklen_t len;
 	int sk, opt, ret;
 
 	dprint(FD_NET, "starting server\n");