This avoids a fairly common issue in which a developer cuts and pastes a
structure definition and forgets to update the structure name inside the
OFP_ASSERT, so that the new structure's size doesn't really get checked at
all.
Without this commit, many of the unit tests for ofp-print.c fail with bus
errors on RISC architectures (tested on sparc) and presumably so would any
other code that uses these same struct members.