Documentation/accounting: Fix typo in taskstats-struct.rst

Documentation/accounting: Fix typo in taskstats-struct.rst

Corrected a typo in the 'taskstats-struct.rst' documentation. The macro
name 'TAKSTATS_VERSION' was mistakenly mentioned instead of the correct
'TASKSTATS_VERSION'. The corrected line now references the proper macro
'TASKSTATS_VERSION', defined in '<linux/taskstats.h>'.

Signed-off-by: Sarveshwaar SS <sarvesh20123@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20241208083320.16190-1-sarvesh20123@gmail.com