kconfig/conf: mark xfgets() private

This function has not much reason to be public. In the mean time, convert
declaration from K&R C to ISO C.
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>

scripts/kconfig/conf.c

@@ -18,6 +18,7 @@
 
 static void conf(struct menu *menu);
 static void check_conf(struct menu *menu);
+static void xfgets(char *str, int size, FILE *in);
 
 enum input_mode {
 	oldaskconfig,
@@ -672,13 +673,11 @@ int main(int ac, char **av)
 	}
 	return 0;
 }
+
 /*
  * Helper function to facilitate fgets() by Jean Sacren.
  */
-void xfgets(str, size, in)
-	char *str;
-	int size;
-	FILE *in;
+void xfgets(char *str, int size, FILE *in)
 {
 	if (fgets(str, size, in) == NULL)
 		fprintf(stderr, "\nError in reading or end of file.\n");

scripts/kconfig/lkc.h

@@ -76,9 +76,6 @@ void zconf_nextfile(const char *name);
 int zconf_lineno(void);
 const char *zconf_curname(void);
 
-/* conf.c */
-void xfgets(char *str, int size, FILE *in);
-
 /* confdata.c */
 const char *conf_get_configname(void);
 const char *conf_get_autoconfig_name(void);