[Patch, libgfortran] Fix PR23154 Currupt string and segfault in formatted read.

[Jerry DeLisle]

Could not come up with a test case.  The bug manifests itself pretty obscurely. 
  In this case almost obvious was difficult to find.  :-)

Bootstrapped and regression tested on 4.0 branch as well.

Committed to mainline and 4.0

2005-08-08  Jerry DeLisle  <jvdelisle@verizon.net>

         PR libfortran/23154
         * io/transfer.c (data_transfer_init): Initialize
         current_unit->bytes_left for a read.