eicon: Fixed checkpatch warning

drivers/isdn/hardware/eicon/diva_didd.c:32:6: warning: symbol
'DRIVERRELEASE_DIDD' was not declared. Should it be static?
Signed-off-by: Andreea Hodea <hodea_andreea@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/hardware/eicon/diva_didd.c

@@ -29,7 +29,7 @@ static char *main_revision = "$Revision: 1.13.6.4 $";
 static char *DRIVERNAME =
 	"Eicon DIVA - DIDD table (http://www.melware.net)";
 static char *DRIVERLNAME = "divadidd";
-char *DRIVERRELEASE_DIDD = "2.0";
+static char *DRIVERRELEASE_DIDD = "2.0";
 
 MODULE_DESCRIPTION("DIDD table driver for diva drivers");
 MODULE_AUTHOR("Cytronics & Melware, Eicon Networks");