All callers of kmap_atomic_primary() use __KM_CACHE, so it can be
removed safely, and __kmap_atomic_primary() only check if 'type' if
__KM_CACHE or not, so 'type' can be changed to a boolean as well.

Ditto for kunmap_atomic_primary()/__kunmap_atomic_primary().
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NCong Wang <amwang@redhat.com>