staging: brcm80211: remove checkpatch errors found in fullmac

A checkpatch run was done over the complete source files to determine
how much coding style issues there are in the driver. This patch fixes
the checkpatch errors in fullmac driver brcmfmac listed below.

ERROR: do not initialise globals to 0 or NULL
+uint dhd_poll = false;
--
ERROR: do not use assignment in if condition
+       if (!ifp && !(ifp = kmalloc(sizeof(dhd_if_t), GFP_ATOMIC))) {
--
ERROR: do not use assignment in if condition
+       if (unlikely(!(wl_cfg80211_dev &&                               \
--
ERROR: do not initialise statics to 0 or NULL
+       static bool iscan_pass_abort = false;
--

Signed-off-by: Arend van Spriel <arend@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>