btrfs-tools: upgrade 6.8 -> 6.8.1

Changelog:
===========
* mkfs: fix writing on zoned device when block-group-tree is selected
* tune: fix writing on zoned device with option --convert-to-block-group-tree
* check:
   * more progress and error messages
   * unify handling of unknown command line options with other commands
* subvolume delete: remove options --delete-qgroup and --no-delete-qgroup
  (added in 6.6.3), qgroup deletion does not always work due to delayed
  background processing of subvolume or set value in
  sysfs:ggroup/drop_subtree_threshold
* other:
   * misc refactoring
   * error handling fixes reported by gcc -fanalyzer
   * documentation updates
   * new and updated tests

(From OE-Core rev: 8fd6322166d9e7d9e1ba61e18dd0b28db1fb95a7)

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/btrfs-tools/btrfs-tools_6.8.1.bb

@@ -18,7 +18,7 @@ DEPENDS = "util-linux zlib"
 SRC_URI = "git://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git;branch=master;protocol=https \
            file://0001-Add-a-possibility-to-specify-where-python-modules-ar.patch \
            "
-SRCREV = "3793e987d2b4e878410da16f33d963043d137d48"
+SRCREV = "5d97c32d6f94cf6f473a5f82964e3edaeb1b146e"
 S = "${WORKDIR}/git"
 
 PACKAGECONFIG ??= " \