source/sink: rename antennas to express their function

lib/fcd/fcd_source.cc

@@ -241,5 +241,5 @@ std::string fcd_source::set_antenna( const std::string & antenna, size_t chan )
 
 std::string fcd_source::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "RX";
 }

lib/file/file_source_c.cc

@@ -200,11 +200,7 @@ double file_source_c::get_gain( const std::string & name, size_t chan )
 
 std::vector< std::string > file_source_c::get_antennas( size_t chan )
 {
-  std::vector< std::string > antennas;
-
-  antennas += get_antenna(chan);
-
-  return antennas;
+  return std::vector< std::string >();
 }
 
 std::string file_source_c::set_antenna( const std::string & antenna, size_t chan )
@@ -214,5 +210,5 @@ std::string file_source_c::set_antenna( const std::string & antenna, size_t chan
 
 std::string file_source_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "";
 }

lib/hackrf/hackrf_sink_c.cc

@@ -665,7 +665,7 @@ std::string hackrf_sink_c::set_antenna( const std::string & antenna, size_t chan
 
 std::string hackrf_sink_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "TX/RX";
 }
 
 double hackrf_sink_c::set_bandwidth( double bandwidth, size_t chan )

lib/hackrf/hackrf_source_c.cc

@@ -643,7 +643,7 @@ std::string hackrf_source_c::set_antenna( const std::string & antenna, size_t ch
 
 std::string hackrf_source_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "TX/RX";
 }
 
 double hackrf_source_c::set_bandwidth( double bandwidth, size_t chan )

lib/miri/miri_source_c.cc

@@ -448,5 +448,5 @@ std::string miri_source_c::set_antenna( const std::string & antenna, size_t chan
 
 std::string miri_source_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "RX";
 }

lib/osmosdr/osmosdr_src_c.cc

@@ -543,5 +543,5 @@ std::string osmosdr_src_c::set_antenna( const std::string & antenna, size_t chan
 
 std::string osmosdr_src_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "RX";
 }

lib/rtl/rtl_source_c.cc

@@ -682,5 +682,5 @@ std::string rtl_source_c::set_antenna( const std::string & antenna, size_t chan
 
 std::string rtl_source_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "RX";
 }

lib/rtl_tcp/rtl_tcp_source_c.cc

@@ -461,5 +461,5 @@ std::string rtl_tcp_source_c::set_antenna( const std::string & antenna, size_t c
 
 std::string rtl_tcp_source_c::get_antenna( size_t chan )
 {
-  return "ANT";
+  return "RX";
 }