brcmfmac: fix memory leak in brcmf_flowring_add_tdls_peer()

In the error paths in brcmf_flowring_add_tdls_peer() the allocated
resource should be freed.

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>