libkmod: swap alloca usage for a few assert_cc

libkmod: swap alloca usage for a few assert_cc

Since all the compression magic is always available now, we don't need
to loop at runtime nor use alloca - latter of which comes with a handful
of caveats.

Simply throw in a few assert_cc(), which will trigger at build-time.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>