brcmfmac: make brcmf_proto_hdrpull() return struct brcmf_if instance

brcmfmac: make brcmf_proto_hdrpull() return struct brcmf_if instance

commit 796cfb65e3ed01a9b08e3a0b93e34120c54bbbd2 upstream.

Avoid spreading the ifidx in the driver, but have it return the
struct brcmf_if instance.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16:
 - Drop changes to PCIe bus support
 - Adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>