octeontx2-af: Remove set but not used variable 'block'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/ethernet/marvell/octeontx2/af/rvu_npa.c: In function 'rvu_npa_init':
drivers/net/ethernet/marvell/octeontx2/af/rvu_npa.c:446:20: warning:
 variable 'block' set but not used [-Wunused-but-set-variable]

It never used since introduction in
commit 7a37245e

 ("octeontx2-af: NPA block admin queue init")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>