crypto: crypto4xx - fix off-by-one AES-OFB

crypto: crypto4xx - fix off-by-one AES-OFB

I used aes-cbc as a template for ofb. But sadly I forgot
to update set_key method to crypto4xx_setkey_aes_ofb().

this was caught by the testmgr:
alg: skcipher: Test 1 failed (invalid result) on encr. for ofb-aes-ppc4xx
00000000: 76 49 ab ac 81 19 b2 46 ce e9 8e 9b 12 e9 19 7d
00000010: 50 86 cb 9b 50 72 19 ee 95 db 11 3a 91 76 78 b2
00000020: 73 be d6 b8 e3 c1 74 3b 71 16 e6 9e 22 22 95 16
00000030: 3f f1 ca a1 68 1f ac 09 12 0e ca 30 75 86 e1 a7

With the correct set_key method, the aes-ofb cipher passes the test.

name         : ofb(aes)
driver       : ofb-aes-ppc4xx
module       : crypto4xx
priority     : 300
refcnt       : 1
selftest     : passed
internal     : no
type         : ablkcipher
async        : yes
blocksize    : 16
min keysize  : 16
max keysize  : 32
ivsize       : 16
geniv        : <default>

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>