libdhcpcd: Work once more with data which does not yield an interface

Such has INFORM6.
An interface could not be created for other reasons, so just read
all the data and try to create all interfaces from it.

Author: geki-yaba

src/libdhcpcd/dhcpcd.c

@@ -1071,8 +1071,9 @@ dhcpcd_open(DHCPCD_CONNECTION *con, bool privileged)
 	/* We don't dispatch each interface here as that
 	 * causes too much notification spam when the GUI starts */
 	for (n = 0; n < nifs; n++) {
-		if (dhcpcd_read_if(con, con->command_fd) == NULL)
-			goto err_exit;
+		/* Some interface states we do not create an interface for
+		 * such as DHS_INFORM. */
+		dhcpcd_read_if(con, con->command_fd);
 	}
 
 	update_status(con, DHC_UNKNOWN);