crypto: nx - do not emit extra output if status is disabled

If the device-tree indicates the nx-842 device's status is 'disabled',
we emit two messages:

nx_compress_pseries ibm,compression-v1: nx842_OF_upd_status: status 'disabled' is not 'okay'.
nx_compress_pseries ibm,compression-v1: nx842_OF_upd: device disabled

Given that 'disabled' is a valid state, and we are going to emit that
the device is disabled, only print out a non-'okay' status if it is not
'disabled'.

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>