Zabbix

...G...... [ZBX-11902] fixed useless check

No need to check for -1 if we don't handle the two cases differently.
Just check if what the function return is different than 1 and write
the error message in all the cases.
This is a small tweak to the previous fix. No functional changes.

Spotted by Sasha.

[svn merge ^/branches/dev/ZBX-11902]