"Deferred" was misspelled as "differed" in some comments, correct this
typo,

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-Id: <20200214155748.0896B745953@zero.eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>