dmraid: require kpartx binary

dmraid requires kpartx to activate device mapper.
But kpartx is only a recommend dependency.

Check for kpartx's existent first.

Signed-off-by: Doan Tran Cong Danh <congdanhqx@gmail.com>

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

@@ -6,6 +6,7 @@ check() {
     # if we don't have dmraid installed on the host system, no point
     # in trying to support it in the initramfs.
     require_binaries dmraid || return 1
+    require_binaries kpartx || return 1
 
     [[ $hostonly ]] || [[ $mount_needs ]] && {
         for dev in "${!host_fs_types[@]}"; do