brcmfmac: merge two brcmf_err macros into one

This allows simplifying the code by adding a simple IS_ENABLED check for
CONFIG_BRCMDB symbol.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>