fortran: Add default to switch in gfc_trans_transfer [PR117843]

fortran: Add default to switch in gfc_trans_transfer [PR117843]

This fixes a bootstrap failure due to a warning on enum values not being
handled. In this case, it is just checking two values and the rest should
are not handled so adding a default case fixes the issue.

Pushed as obvious.

	PR fortran/117843
gcc/fortran/ChangeLog:

	* trans-io.cc (gfc_trans_transfer): Add default case.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
(cherry picked from commit 48b72743b0e29871171593fe34856da62d954750)