Running check-snmpt-disk.rb results in NoMethodError

[khourybrazil]

When I run check-snmpt-disk.rb it fails:

check-snmp-disk.rb -h 192.168.1.1 -C community -m /data/somemount -w 80 -c 95
CheckSNMP UNKNOWN: An unknown error occured: #<NoMethodError: undefined method `/' for #<SNMP::Integer:0x0000555abd4a2730 @value=364993517>>

When I change dev_used.value to dev_used.value.to_f (or .to_i) on this line it returns the expected output:

CheckSNMP OK: All disk usage under 80%

I was going to open a quick PR but I noticed this line was changed intentionally in the past:
0a657ad

I've verified this behavior on Alpine using ruby 2.4.4p296 and macOS using ruby 2.3.7p456.

Thanks,
Khoury