is_cpu_write_access is only set if tb_invalidate_phys_page_range is called
from tb_invalidate_phys_page_fast, and hence from notdirty_mem_write.
However:

- the code bitmap can be built directly in tb_invalidate_phys_page_fast
  (unconditionally, since is_cpu_write_access would always be passed as 1);

- the virtual address is not needed to mark the page as "not containing
  code" (dirty code bitmap = 1), so we can also remove that use of
  is_cpu_write_access.  For calls of tb_invalidate_phys_page_range
  that do not come from notdirty_mem_write, the next call to
  notdirty_mem_write will notice that the page does not contain code
  anymore, and will fix up the TLB entry.

The parameter needs to remain in order to guard accesses to cpu->mem_io_pc.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>