fs-ro: show mount point info on first line when there is only one hit

[kbucheli]

As the first line is treated specially, eg. show in the Icingaweb overview, it would be handy if it would list there when there is just one mount point hit. I guess these are the most interesting cases.

Tests: Single hit

[root@test-004 ~]# monitoring-plugins/check-plugins/fs-ro/fs-ro 
read-only mount point found: /dev/loop0 on /mnt/iso (type iso9660)
[root@test-004 ~]#

Multiple hits:

[root@test-003 ~]# monitoring-plugins/check-plugins/fs-ro/fs-ro 
4 read-only mount points found:
* newperf on /gpfs/perf (type gpfs)
* newtiered on /gpfs/tiered (type gpfs)
* admin on /das/support (type gpfs)
* newphoto on /gpfs/photo (type gpfs)
[root@test-003 ~]# 

PS:

• The /dev/loop* ignore does not work, as this is the device, not the mountpoint
• Would it not make sense to exclude network filesystems? There you do not have the automatic conversion from rw to ro on filesystem corruption.

[markuslf]

Improved the code afterwards and added one more unit test.