staging: brcm80211: replaced WL_ERROR in rest of softmac.

Code cleanup. Replaced proprietary function by wiphy_err(). Removed
WL_ERROR() on spots where struct wlc was not available and message
was redundant.

Cc: devel@linuxdriverproject.org
Cc: linux-wireless@vger.kernel.org
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Henry Ptasinski <henryp@broadcom.com>
Cc: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>