Revert "[wpa_supplicant] Cumulative patch from b8491ae5a"

This reverts commit 878cf7bcbf2d7d8f08c3d060b8c5fbfcf0743eda.

Reason for revert: git_master/sdk_phone_armv7-sdk

Change-Id: I6070fc5c1f9c20867f6dfce90e529e35578d572e
diff --git a/src/crypto/sha1.c b/src/crypto/sha1.c
index 76d7a68..8fce139 100644
--- a/src/crypto/sha1.c
+++ b/src/crypto/sha1.c
@@ -86,8 +86,7 @@
 	_addr[1] = mac;
 	_len[1] = SHA1_MAC_LEN;
 	ret = sha1_vector(2, _addr, _len, mac);
-	forced_memzero(k_pad, sizeof(k_pad));
-	forced_memzero(tk, sizeof(tk));
+	os_memset(k_pad, 0, sizeof(k_pad));
 	return ret;
 }