drivers/net: appletalk/cops: remove redundant if statement and mask

The two different assignments for pkt_len are actually the same and
so the if statement is redundant and can be removed.  Masking a u8
return value from inb() with 0xFF is also redundant and can also be
emoved.

Similarly, the two different outb calls are identical as the mask
of 0xff on the second outb is redundant since a u8 is being written,
so the if statement is also redundant and can be also removed.

Detected by CoverityScan, CID#1475639 ("Identical code for different
branches")

V2: Remove the if statement for the outb calls, thanks to David
Miller for spotting this.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>