tests: net: socketpair: explicit fcntl path on native_posix

Previously, `socketpair()` tests had pulled in the native
`fcntl()` implementation instead of using the Zephyr version
when being run under `native_posix_64`.

Signed-off-by: Christopher Friedt <[email protected]>

Author: cfriedt

tests/net/socket/socketpair/src/_main.h

@@ -12,16 +12,10 @@
 
 #include <zephyr/logging/log.h>
 #include <zephyr/net/socket.h>
+#include <zephyr/posix/fcntl.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/ztest.h>
 
-#ifdef CONFIG_ARCH_POSIX
-#include <fcntl.h>
-#else
-#include <zephyr/posix/fcntl.h>
-#include <zephyr/posix/unistd.h>
-#endif
-
 LOG_MODULE_DECLARE(net_test, CONFIG_NET_SOCKETS_LOG_LEVEL);
 
 extern struct k_work_q test_socketpair_work_q;