fate: Skip the checkasm test if CONFIG_STATIC is disabled

When building DLLs with MSVC, CONFIG_STATIC is disabled (see
d66c52c2b3694 for a more verbose explanation) since the built
object files can't be linked statically (which checkasm does).

This worked up until recently, only by luck.

Signed-off-by: Martin Storsjö <martin@martin.st>
