Fix build-it compilation regression

Accidentally introduced by 4ea3f86. The BEGIN CSTYLE block cannot
appear half way through a continued #define.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5643
Closes #5644