[krb5-auth-dialog] lexer: Add declaration

[Guido Günther <guidog src gnome org>]

commit 6e7fabff20808aadcf21460949329d72940ccf81
Author: Guido Günther <agx sigxcpu org>
Date:   Mon Feb 8 16:43:55 2021 +0100

    lexer: Add declaration
    
    Just to make the compiler happy

 etpo/lexer.l | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/etpo/lexer.l b/etpo/lexer.l
index 4cdec06..eb6d1a5 100644
--- a/etpo/lexer.l
+++ b/etpo/lexer.l
@@ -62,6 +62,8 @@ error_code|ec         { yylval.sval = g_strdup(yytext);
 static GList *filenames = NULL, *filename = NULL;
 const char *currentfile = NULL;
 
+int yyerror(void);
+
 int
 yyerror(void)
 {