convert.cvs: Initialize state variable and abort on cvs error
Fix as proposed by Frank Kingswood.
Avoids
UnboundLocalError: local variable 'mode' referenced before assignment
when cvs fails.
This alsa partially fixes issue1592.
adding a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24