poky: reset subtree on master HEAD(a88251b3e7)

As part of the last subtree update, I used master-next as the
subtree basis because there was a fix we needed in order to get QEMU
to pass.  I didn't realize that master-next deviated (because they use
to just have short-term patches in it).  Reset the content to the same
fix but from the master branch.

Change-Id: Ic7d2f0ac42e9da3eb263586b26ba56d8798d5bcf
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/poky/documentation/dev-manual/disk-space.rst b/poky/documentation/dev-manual/disk-space.rst
index 6d1638a..efca826 100644
--- a/poky/documentation/dev-manual/disk-space.rst
+++ b/poky/documentation/dev-manual/disk-space.rst
@@ -49,7 +49,7 @@
 covering multiple releases. It won't work either on limited environments
 such as BSD based NAS::
 
-   sstate-cache-management.sh --remove-duplicated --cache-dir=build/sstate-cache
+   sstate-cache-management.py --remove-duplicated --cache-dir=sstate-cache
 
 This command will ask you to confirm the deletions it identifies.
 Run ``sstate-cache-management.sh`` for more details about this script.