Fix error handling for "zpool online -e".
The error handling code around zpool_relabel_disk() is either inexistent
or wrong. The function call itself is not checked, and
zpool_relabel_disk() is generating error messages from an unitialized
buffer.
Before:
- zpool online -e homez sdb; echo $? `: cannot relabel 'sdb1': unable to open device: 2 0
After:
- zpool online -e homez sdb; echo $? cannot expand sdb: cannot relabel 'sdb1': unable to open device: 2 1
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #808