doc: fix warnings found by Doxygen 1.9.7

src/internet/test/ipv4-list-routing-test-suite.cc

@@ -20,7 +20,8 @@
 #include "ns3/ipv4-routing-protocol.h"
 #include "ns3/test.h"
 
-using namespace ns3;
+namespace ns3
+{
 
 /**
  * \ingroup internet-test
@@ -217,3 +218,5 @@ class Ipv4ListRoutingTestSuite : public TestSuite
 
 static Ipv4ListRoutingTestSuite
     g_ipv4ListRoutingTestSuite; //!< Static variable for test initialization
+
+} // namespace ns3

src/internet/test/ipv6-list-routing-test-suite.cc

@@ -21,7 +21,8 @@
 #include "ns3/ipv6-routing-protocol.h"
 #include "ns3/test.h"
 
-using namespace ns3;
+namespace ns3
+{
 
 /**
  * \ingroup internet-test
@@ -246,3 +247,5 @@ class Ipv6ListRoutingTestSuite : public TestSuite
 
 static Ipv6ListRoutingTestSuite
     g_ipv6ListRoutingTestSuite; //!< Static variable for test initialization
+
+} // namespace ns3

src/wifi/model/wifi-mac.h

@@ -55,7 +55,8 @@ class OriginatorBlockAckAgreement;
 class RecipientBlockAckAgreement;
 
 /**
- * Enumeration for type of station
+ * \ingroup wifi
+ * Enumeration for type of WiFi station
  */
 enum TypeOfStation
 {
@@ -68,7 +69,6 @@ enum TypeOfStation
 
 /**
  * \ingroup wifi
- * \enum WifiMacDropReason
  * \brief The reason why an MPDU was dropped
  */
 enum WifiMacDropReason : uint8_t