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/sha256-prf.c b/src/crypto/sha256-prf.c
index d665a99..722cad6 100644
--- a/src/crypto/sha256-prf.c
+++ b/src/crypto/sha256-prf.c
@@ -102,7 +102,7 @@
 		buf[pos - 1] &= mask;
 	}
 
-	forced_memzero(hash, sizeof(hash));
+	os_memset(hash, 0, sizeof(hash));
 
 	return 0;
 }