daemon: parted: part-get-name: Don't leak partition type string.

Found by './configure --enable-valgrind-daemon'.

This fixes commit 820b87016794116c783bd224f2e776cfdf65108e.
make-fs: Check for error return from guestfs_statvfs.

Found by Coverity.
make-fs: Close FILE* along error path.

Found by Coverity.
rescue: Don't leak various variables when using --suggest option with multi-boot guests.

This fixes a leak which was introduced in
commit 4255db65e58a86148ec291a7416a1148c453d926.

Found by Coverity.
rescue: Add a regression test for virt-rescue --suggest option.