lvm: Only activate a given vg+lv once.

Due to the way the main loop runs to detect partions, the same one
might be included twice (albeit via different symlinks.

This code simply prevents the same combo being activated twice.

A better fix might simply be to not include duplicate (after
resolving symlinks) entries in the host_fs_types variable.

modules.d/90lvm/module-setup.sh

@@ -3,7 +3,7 @@
 # ex: ts=8 sw=4 sts=4 et filetype=sh
 
 check() {
-    local _rootdev
+    local _rootdev _activated
     # No point trying to support lvm if the binaries are missing
     type -P lvm >/dev/null || return 1
 
@@ -15,7 +15,10 @@ check() {
         unset DM_LV_NAME
         eval $(udevadm info --query=property --name=$1|egrep '(DM_VG_NAME|DM_LV_NAME)=')
         [[ ${DM_VG_NAME} ]] && [[ ${DM_LV_NAME} ]] || return
-        echo " rd.lvm.lv=${DM_VG_NAME}/${DM_LV_NAME} " >> "${initdir}/etc/cmdline.d/90lvm.conf"
+        if ! strstr " ${_activated[*]} " " ${DM_VG_NAME}/${DM_LV_NAME} "; then
+            echo " rd.lvm.lv=${DM_VG_NAME}/${DM_LV_NAME} " >> "${initdir}/etc/cmdline.d/90lvm.conf"
+            push _activated "${DM_VG_NAME}/${DM_LV_NAME}"
+        fi
     }
 
     [[ $hostonly ]] || [[ $mount_needs ]] && {