Document an additional error return value. The connect(2) call can also

Document an additional error return value.  The connect(2) call can also
return EACCES on non-Unix domain sockets as demonstrated by the
following program:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int
main(int argc, char *argv[])
{
	struct sockaddr_in rem_addr;
	int sock;

	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		perror("socket");
		exit(1);
	}

	bzero((char *)&rem_addr, sizeof(rem_addr));
	rem_addr.sin_family = AF_INET;
	rem_addr.sin_addr.s_addr = INADDR_NONE;
	rem_addr.sin_port = htons(10000);

	if (connect(sock, (struct sockaddr *)&rem_addr,
sizeof(rem_addr)) < 0) {
		perror("connect");
		exit(1);
	}
}

The call chain returning this value is probably:

kern/uipc_syscalls.c:connect
kern/uipc_socket.c:soconnect
netinet/tcp_usrreq.c:tcp_usr_connect
netinet/tcp_output.c:tcp_output
netinet/ip_output.c:ip_output

Reviewed by:	schweikh (mentor)
MFC after:	2 weeks