History: no prompting on exit errors, because making the user hit Enter when

History: no prompting on exit errors, because making the user hit Enter when
there's an error saving history state at exit is pointless and annoying.
Just notify the user and move on.
Patch by Mike Frysinger, tweaked and extended by Benno.

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@5507 35c25a1d-7b9e-4130-9fde-d3aeb78583b8