Description for -M was the wrong way around (#1746)

Using -M should show the mountpoint instead of the device the
file system originated from.
Seems like this was not the case for a long time and now
the default is to show the mount point. Using `-M` reverts
to showing the (block) device instead.
The usage Description was adjusted with this commit.

1 files changed, 1 insertions, 1 deletions

diff --git a/plugins/check_disk.c b/plugins/check_disk.c
index 9652f45..66c5dd3 100644
--- a/plugins/check_disk.c
+++ b/plugins/check_disk.c
@@ -961,7 +961,7 @@ print_help (void)
   printf ("    %s\n", _("Only check local filesystems against thresholds. Yet call stat on remote filesystems"));
   printf ("    %s\n", _("to test if they are accessible (e.g. to detect Stale NFS Handles)"));
   printf (" %s\n", "-M, --mountpoint");
-  printf ("    %s\n", _("Display the mountpoint instead of the partition"));
+  printf ("    %s\n", _("Display the (block) device instead of the mount point"));
   printf (" %s\n", "-m, --megabytes");
   printf ("    %s\n", _("Same as '--units MB'"));
   printf (" %s\n", "-A, --all");