check_file_age: Provide performance data
Revert "Make use of xasprintf instead of asprintf"

This reverts commit a143739ed286cf9ae003792dbb1ce26ce43f3312.

Our current setup doesn't allow lib/*.c files to call functions defined
in plugins/utils.[ch].
check_ifstatus: Fix "-n" and "-u" options

Ignore interface if it's specified via "-n" OR "-u", not just when it's
specified via "-n" AND "-u".
Removing the spec file, as it's broken
Even we have none feedback in PR #1283