Fixed wording of the -p flag

Before it read as "to the client from the AP and 5 from the AP to the client" which is the same thing twice. Based on this code

deauth_pkt1 = Dot11(addr1=client, addr2=ap, addr3=ap)/Dot11Deauth()
deauth_pkt2 = Dot11(addr1=ap, addr2=client, addr3=client)/Dot11Deauth()

it should be "from the client to the AP and from the AP to the client"
Merge pull request #4 from ThaWeatherman/master

Fixed wording of the -p flag