RFA: Small fix to valops.c (value_assign)

[Andrew Cagney]

Fernando Nasser wrote:

2000-06-08  Fernando Nasser  <fnasser@cygnus.com>

      * valops.c (value_assign): Adjust the length to take into
      consideration that we are not starting from the beginning.

Yes, ok.  That should stop a few bogus register writes.

	Andrew