isdn: hysdn: Kill (partially buggy) CVS regision log reporting.

Some cases try to modify const strings, and in any event the
CVS revision strings have not changed in over ten years making
these printouts completely worthless.

Just kill all of this stuff off.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>