preproc: Fix in accessing the definition structure of a single-line macro

Determining whether we should warn on defining a single-line macro, with a
name and a certain number of parameters, call a helper function,
smacro_defined(). It does not always return the address of the definition
structure.

Fix the code to be cautiously accessing the definition structure.

Fixes: e91f5cc1322e ("preproc: fix %undef of macro aliases, and add
%ifdefalias")

Reported-by: Dale Curtis <dalecurtis@chromium.org>
Link: https://bugzilla.nasm.us/show_bug.cgi?id=3392659
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>

0 files changed, 0 insertions, 0 deletions