load: param onlyif failed on Exec[modprobe -r MODULENAME]

Hi,

On Ubuntu Trusty, when i tried to do this:
  kmod::blacklist { 'MODULENAME':
  }

I got this error:
--------------------
Info: Caching catalog for media.home.org Error: Failed to apply catalog:
Parameter onlyif failed on Exec[modprobe -r xpad]: 'egrep -q '^modname ' /proc/modules'
is not qualified and no path was specified. Please qualify the command or
specify a path. at /etc/puppet/modules/kmod/manifests/load.pp:33 Wrapped
exception: 'egrep -q '^modname ' /proc/modules' is not qualified and no path was
specified. Please qualify the command or specify a path.

It happened because modprobe and egrep were not found. I added the path variable and it works fine now.