samples: net: latmon: Use native networking API directly

This subsystem does not use the POSIX_API, and the sample only used one
call to the POSIX API to close a socket instead of using the native
networking API.
Let's just use the native networking API, so we avoid pulling-in more
dependencies.

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

samples/net/latmon/prj.conf

@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (c) 2025 Jorge Ramirez-Ortiz <[email protected]>
 
-CONFIG_POSIX_API=y
-
 # General config
 CONFIG_LOG=y
 CONFIG_GPIO=y

samples/net/latmon/src/main.c

@@ -13,7 +13,6 @@ LOG_MODULE_REGISTER(sample_latmon, LOG_LEVEL_DBG);
 #include <zephyr/net/socket.h>
 #include <zephyr/spinlock.h>
 #include <zephyr/sys/atomic.h>
-#include <zephyr/posix/unistd.h>
 
 /*
  * Blink Control
@@ -267,7 +266,7 @@ int main(void)
 	}
 out:
 	k_thread_abort(blink_tid);
-	close(socket);
+	zsock_close(socket);
 
 	return ret;
 }