ath11k: remove redundant num_keep_alive_pattern assignment

There were two asignments to num_keep_alive_pattern, remove the first one which is wrong.

No functional changes. Compile tested only.

Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1600361190-22047-1-git-send-email-kvalo@codeaurora.org