net: capture: Fix the API documentation

The net_capture_send() is only to be called from capture
implementation itself, so the API does not need to be public
thus hide it from generated documentation.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>

include/zephyr/net/capture.h

@@ -166,6 +166,8 @@ static inline int net_capture_disable(const struct device *dev)
 #endif
 }
 
+/** @cond INTERNAL_HIDDEN */
+
 /**
  * @brief Send captured packet.
  *
@@ -192,8 +194,6 @@ static inline int net_capture_send(const struct device *dev, struct net_if *ifac
 #endif
 }
 
-/** @cond INTERNAL_HIDDEN */
-
 /**
  * @brief Check if the network packet needs to be captured or not.
  *        This is called for every network packet being sent.