also change the --help output to reflect that check_disk_smb defaults to empty passwords

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1164 f882894a-f735-0410-b71e-b25c423dba1c

plugins-scripts/check_disk_smb.pl

@@ -252,7 +252,7 @@ Perl Check SMB Disk plugin for Nagios
 -u, --user=STRING
    Username to log in to server. (Defaults to \"guest\")
 -p, --password=STRING
-   Password to log in to server. (Defaults to \"guest\")
+   Password to log in to server. (Defaults to an empty password)
 -w, --warning=INTEGER or INTEGER[kMG]
    Percent of used space at which a warning will be generated (Default: 85%)