File audio output: remove useless longhelp

We have the format selection for that
(cherry picked from commit 945943a2)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/audio_output/file.c

@@ -78,9 +78,6 @@ static void    Play        ( audio_output_t *, block_t * );
  * Module descriptor
  *****************************************************************************/
 #define FORMAT_TEXT N_("Output format")
-#define FORMAT_LONGTEXT N_("One of \"u8\", \"s8\", \"u16\", \"s16\", " \
-    "\"u16_le\", \"s16_le\", \"u16_be\", \"s16_be\", \"fixed32\", " \
-    "\"float32\" or \"spdif\"")
 
 #define CHANNELS_TEXT N_("Number of output channels")
 #define CHANNELS_LONGTEXT N_("By default (0), all the channels of the incoming " \
@@ -116,7 +113,7 @@ vlc_module_begin ()
     add_savefile( "audiofile-file", "audiofile.wav", FILE_TEXT,
                   FILE_LONGTEXT, false )
     add_string( "audiofile-format", "s16",
-                FORMAT_TEXT, FORMAT_LONGTEXT, true )
+                FORMAT_TEXT, FORMAT_TEXT, true )
         change_string_list( format_list, 0, 0 )
     add_integer( "audiofile-channels", 0,
                  CHANNELS_TEXT, CHANNELS_LONGTEXT, true )