Correct typo for Raspberry Pi ddrescue command.

Spotted here:
https://ubuntu-mate.community/t/potential-typo-in-tutorial/19298

pages/raspberry-pi.md

@@ -111,7 +111,7 @@ for example:
 
     sudo apt-get install gddrescue xz-utils
     unxz ubuntu-mate-18.04.2-beta1-desktop-armhf+raspi-ext4.img.xz
-    sudo ddrescue -D --force ubuntu-mate-18.04.2-beta1-desktop-armhf+raspi-ext4.img.xz /dev/sdx
+    sudo ddrescue -D --force ubuntu-mate-18.04.2-beta1-desktop-armhf+raspi-ext4.img /dev/sdx
 
 The microSDHC or USB stick may be presented on any `/dev/sdX` so use the command
 `lsblk` to check.
@@ -310,4 +310,4 @@ and/or VC-1 licenses from the [Raspberry Pi Store](http://www.raspberrypi.com/li
 
 Thse images are not official Ubuntu products and are community
 supported by the Ubuntu MATE team. Please post feedback and
-issues on the [dedicated community forum](https://ubuntu-mate.community/c/support/raspberry-pi-2).
+issues on the [dedicated community forum](https://ubuntu-mate.community/c/support/raspberry-pi-2).