Fix linux-2.6 in download URL for RedHat x86_64

Staring with 9.0.5 Splunk changed the filename of the RPM. It no longer includes
"linux-2.6", thus we need to adapt to this change.

Only checked for RedHat x86_64, other releases might be affected as well. If so,
apply the $linux_prefix variable where needed.

manifests/params.pp

@@ -298,6 +298,14 @@
     default:   { $package_provider = undef } # Don't define a $package_provider
   }
 
+  # Download URLs changed starting from 9.0.5 for RPMs.
+  # Splunk no longer includes "-linux-2.6-".
+  $linux_prefix = versioncmp($version, '9.0.5') ? {
+    1  => '.',
+    0  => '.',
+    -1 => '-linux-2.6-',
+  }
+
   # Settings specific to an architecture as well as an OS family
   case "${facts['os']['family']} ${facts['os']['architecture']}" {
     'RedHat i386': {
@@ -306,7 +314,7 @@
       $enterprise_package_name = 'splunk'
     }
     'RedHat x86_64': {
-      $package_suffix          = "${version}-${build}-linux-2.6-x86_64.rpm"
+      $package_suffix          = "${version}-${build}${linux_prefix}x86_64.rpm"
       $forwarder_package_name  = 'splunkforwarder'
       $enterprise_package_name = 'splunk'
     }