iscontrol: move definition of vflag/iscsidev to iscontrol.c

Mark the declaration extern as these are used elsewhere; this fixes the
build with -fno-common.

MFC after:	3 days

sbin/iscontrol/iscontrol.c

@@ -82,6 +82,9 @@ token_t	DigestMethods[] = {
      {0, 0}
 };
 
+int	vflag;
+char	*iscsidev;
+
 u_char	isid[6 + 6];
 /*
  | Default values

sbin/iscontrol/iscontrol.h

@@ -149,8 +149,8 @@ int	recvpdu(isess_t *sess, pdu_t *pp);
 
 int	lookup(token_t *tbl, char *m);
 
-int	vflag;
-char	*iscsidev;
+extern int	vflag;
+extern char	*iscsidev;
 
 void	parseArgs(int nargs, char **args, isc_opt_t *op);
 void	parseConfig(FILE *fd, char *key, isc_opt_t *op);