no perfdata using disk -u %

[xoroz]

just a simple fix to remove extra space when running

perl check_stats2.pl -D -w 7 -c 4 -u % -p /mnt/storage/Archive_run
DISK OK used : /mnt/storage/Archive_run 21.59% free | /mnt/storage/Archive_run=78.41%

edit:
414: $perfdata .= " $mountpoint=$percentused".'%';