zfs: merge openzfs/zfs@a94860a6d
Notable upstream pull request merges:
#15511 92dc4ad83 Consider dnode_t allocations in dbuf cache size accounting
#15514 22c8c33a5 Use abd_zero_off() where applicable
#15515 5a3bffab1 ZIO: Optimize zio_flush()
#15527 cd67bc0ae freebsd: remove __FBSDID macro use
Obtained from: OpenZFS
OpenZFS commit: a94860a6dee1c07bb96ee36dafcba40b804560cc