nl80211: minor correction in sample wowlan mask calculation

The match 00:xx:00:00:xx:00:00:00:00:xx:xx:xx (where xx indicates
"don't care") should be represented by a pattern of twelve zero
bytes, and a mask of "0xed,0x01", not "0xed,0x07".

mask_len = (pat_len + 7) / 8 = (12 + 7) / 8 = 2
Hence the mask will be of 2 bytes.
Replace each valid byte in pattern by 1 and don't care byte by 0:
10110111 1000 (0000)

1st byte of pattern corresponds to lower order bit in first byte
of mask. And 9th byte of pattern corresponds to lower order bit
in second byte of mask. With this logic the mask will be
11101101 00000001 = 0xed 0x01

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>