brcmfmac: (clean) Move tracepoint related function.

__brcmf_err is a tracepoint specific function. Move it to
tracepoint.c.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --cc drivers/net/wireless/brcm80211/brcmfmac/dhd_common.c
Simple merge

diff --cc drivers/net/wireless/brcm80211/brcmfmac/tracepoint.c
Simple merge