Coverity: Dereference after null check (FORWARD_NULL)
var_compare_op: Comparing "log" to null implies that "log" might be null.
var_deref_model: Passing null pointer "&log->log_lock" to function
"__wt_spin_destroy(WT_SESSION_IMPL *, WT_SPINLOCK *)", which
dereferences it.[show details]
Should never happen, but lint points out session can theoretically be
a NULL value at the end of this loop.