bna: Remove unnecessary self assignment

Clang warns when a variable is assigned to itself.

drivers/net/ethernet/brocade/bna/bna_enet.c:1800:9: warning: explicitly
assigning value of variable of type 'int' to itself [-Wself-assign]
        for (i = i; i < (bna->ioceth.attr.num_ucmac * 2); i++)
             ~ ^ ~
drivers/net/ethernet/brocade/bna/bna_enet.c:1835:9: warning: explicitly
assigning value of variable of type 'int' to itself [-Wself-assign]
        for (i = i; i < (bna->ioceth.attr.num_mcmac * 2); i++)
             ~ ^ ~
2 warnings generated.

Link: https://github.com/ClangBuiltLinux/linux/issues/110


Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>