doc: gpt: fix example of echoing variable

Fixes: 44c5d7764bf4 ("doc: Add gpt command documentation")
Signed-off-by: Tom Fitzhenry <tom@tom-fitzhenry.me.uk>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/doc/usage/cmd/gpt.rst b/doc/usage/cmd/gpt.rst
index f6115ec..cbbe44a 100644
--- a/doc/usage/cmd/gpt.rst
+++ b/doc/usage/cmd/gpt.rst
@@ -156,6 +156,7 @@
 
 Examples
 ~~~~~~~~
+
 Create 6 partitions on a disk::
 
     => setenv gpt_parts 'uuid_disk=bec9fc2a-86c1-483d-8a0e-0109732277d7;
@@ -192,10 +193,9 @@
 Get the list of partition names on the disk::
 
     => gpt enumerate
-    => echo gpt_partition_list
+    => echo ${gpt_partition_list}
     boot rootfs system-data [ext] user modules ramdisk
 
-
 Get the GUID for a disk::
 
     => gpt guid mmc 0
@@ -209,6 +209,7 @@
     => gpt set-bootable mmc 0 boot
 
 Swap the order of the 'boot' and 'rootfs' partition table entries::
+
     => gpt setenv mmc 0 rootfs
     => echo ${gpt_partition_entry}
     2