brcmfmac: only disable clock when brcmf_sdio_bus_init() fails

The condition to disable the clock at the end of brcmf_sdio_bus_init()
was wrong as the bus state is updated by the calling function. Hence,
the clock was always disabled after brcmf_sdio_bus_init() which was
not the intended behaviour.

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