Remove extra parameter from scanhash_asm32.

This `unsigned char *hash1` was preventing compilation on ia32 systems and
it seems to be (apparently) unneeded according to my tests.

This fixes #41.

Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
Merge pull request #43 from rbrito/master

Remove extra parameter from scanhash_asm32.