brcmfmac: Fix memory leak for unpaired brcmf_{alloc/free}

There are missig brcmf_free() for brcmf_alloc(). Fix memory leak
by adding missed brcmf_free().

Reported-by: Jaehoon Chung <jh80.chung@samsung.com>
Fixes: a1f5aac1 ("brcmfmac: don't realloc wiphy during PCIe reset")
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1603849967-22817-1-git-send-email-sw0312.kim@samsung.com