Fix: sessiond: error accounting: wrong sizeof argument cpu_counters

1452205 Wrong sizeof argument

The wrong sizeof value is used in an expression or as argument to a function. The result is an incorrect value that may cause unexpected program behaviors.

In create_uid_accounting_entry: The sizeof operator is invoked on the wrong argument (CWE-569)

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1912964bd1579f3b1ff013000848c28cea6a9d52