hostap: fix sparse warnings

Rewrite AID calculation in handle_pspoll() to avoid truncating bits.
Make hostap_80211_header_parse() static, don't export it.  Avoid
shadowing variables.

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/hostap/hostap_cs.c b/drivers/net/wireless/hostap/hostap_cs.c
index ed4317a..80039a0 100644
--- a/drivers/net/wireless/hostap/hostap_cs.c
+++ b/drivers/net/wireless/hostap/hostap_cs.c
@@ -533,10 +533,10 @@
 do { last_fn = (fn); if ((last_ret = (ret)) != 0) goto cs_failed; } while (0)
 
 #define CFG_CHECK2(fn, retf) \
-do { int ret = (retf); \
-if (ret != 0) { \
-	PDEBUG(DEBUG_EXTRA, "CardServices(" #fn ") returned %d\n", ret); \
-	cs_error(link, fn, ret); \
+do { int _ret = (retf); \
+if (_ret != 0) { \
+	PDEBUG(DEBUG_EXTRA, "CardServices(" #fn ") returned %d\n", _ret); \
+	cs_error(link, fn, _ret); \
 	goto next_entry; \
 } \
 } while (0)