brcm80211: pointless current->files passed to filp_close()

... only needed if it's been in descriptor table
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c

@@ -1182,7 +1182,7 @@ int brcmf_write_to_file(struct brcmf_pub *drvr, const u8 *buf, int size)
 	kfree(buf);
 	/* close file before return */
 	if (fp)
-		filp_close(fp, current->files);
+		filp_close(fp, NULL);
 	/* restore previous address limit */
 	set_fs(old_fs);