ath11k: fix error routine when fallback of add interface fails

When there is an error in add interface process from
ath11k_mac_set_kickout(), the code attempts to handle a
fallback for add_interface. When this fallback succeeds, the
driver returns zero rather than error code. This leads to
success for the non created VAP. In cleanup, driver gets
remove interface callback for the non created VAP and
proceeds to self peer delete request which leads to FW assert.
Since it was already deleted on the fallback of add interface,
return the actual error code instead of fallback return code.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.5.0.1-00729-QCAHKSWPL_SILICONZ-3 v2

Signed-off-by: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1636558557-2874-1-git-send-email-quic_periyasa@quicinc.com