use correct parameter

manifests/keywords.pp

 define gentoo::keywords ($source="", $ensure=present) {
     file { "gentoo_keywords_${name}":
-        target  => "/etc/portage/package.keywords/${name}",
+        path    => "/etc/portage/package.keywords/${name}",
         source  => "${source}",
         ensure  => $ensure,
     }

manifests/mask.pp

 define gentoo::mask ($source="", $ensure=present) {
     file { "gentoo_mask_${name}":
-        target  => "/etc/portage/package.mask/${name}",
+        path    => "/etc/portage/package.mask/${name}",
         source  => "${source}",
         ensure  => $ensure,
     }

manifests/unmask.pp

 define gentoo::unmask ($source="", $ensure=present) {
     file { "gentoo_unmask_${name}":
-        target  => "/etc/portage/package.unmask/${name}",
+        path    => "/etc/portage/package.unmask/${name}",
         source  => "${source}",
         ensure  => $ensure,
     }

manifests/use.pp

 define gentoo::use ($source="", $ensure=present) {
     file { "gentoo_use_${name}":
-        target  => "/etc/portage/package.use/${name}",
+        path    => "/etc/portage/package.use/${name}",
         source  => "${source}",
         ensure  => $ensure,
     }