lr_write_t records that are WR_COPIED have the record data directly
appended to them (see lr_write_t type definition).
The data is copied from the debuf using dmu_read_by_dnode.
This function was called, only for WR_COPIED records, as part of a
short-circuiting if-statement's if-expression.
I found this side-effectful call to dmu_read_by_dnode pretty
hard to spot.
This patch improves readability by moving the call to its own line.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Christian Schwarz <me@cschwarz.com>
Closes#10956