client, event_pipe: explicitly ignore the write() result

On both locations, the result of write() can be ignored safely.  In
event_pipe_emit_fast(), that can only be "EAGAIN", which means that
the pipe buffer is full - no further notification required.  In
client_init(), that would be a fatal connection error, which would be
caught by the next event.

This patch fixes gcc warnings.

src/client.c

@@ -205,7 +205,7 @@ static void client_init(struct client *client, int fd)
 
 	client->permission = getDefaultPermissions();
 
-	write(fd, GREETING, sizeof(GREETING) - 1);
+	(void)write(fd, GREETING, sizeof(GREETING) - 1);
 }
 
 static void free_cmd_list(GSList *list)

src/event_pipe.c

@@ -149,5 +149,5 @@ void event_pipe_emit_fast(enum pipe_event event)
 	assert((unsigned)event < PIPE_EVENT_MAX);
 
 	pipe_events[event] = true;
-	write(event_pipe[1], "", 1);
+	(void)write(event_pipe[1], "", 1);
 }