UPSTREAM: ath10k: fix return value check in wake_tx_q op

ath10k_mac_tx_push_txq returns either a postive integer (length) on
success or a negative error code on error.

The "if (ret) break;" statement will thus always break out of the loop
immediately after ath10k_mac_tx_push_txq has returned (making the loop
pointless).

A side effect of this fix is that we will iterate the queue until
ath10k_mac_tx_push_txq returns -ENOENT. This will make sure the queue is
not added back to ar->txqs when it is empty. This could potentially
improve performance somewhat (I have seen a small improvement with SDIO
devices).

(cherry picked from commit e3148cc5)
(source: https://git.kernel.org/cgit/linux/kernel/git/kvalo/ath.git

)

BUG=b:132147953
TEST=None

Change-Id: I29fb7f7b6157c28a7b9c5a3a25dfbc30a55f289a
Signed-off-by: Erik Stromdahl <erik.stromdahl@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Signed-off-by: Vamsi Singamsetty <vamssi@codeaurora.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1642724


Reviewed-by: Julan Hsu <julanhsu@google.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Julan Hsu <julanhsu@google.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>