DESC
remap_file_pages protection support: fix i386 handler
EDESC
From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

Actually, with the current model, we should get a failure with VMA's mapped
with only PROT_WRITE (even if I wasn't able to verify that in UML, which has
similar code).

To test!
