Avoid -Wuninitialized-const-pointer

Index: 3rdparty/vboot/firmware/lib/tpm_lite/tlcl.c
--- 3rdparty/vboot/firmware/lib/tpm_lite/tlcl.c.orig
+++ 3rdparty/vboot/firmware/lib/tpm_lite/tlcl.c
@@ -822,7 +822,7 @@ uint32_t TlclGetFlags(uint8_t* disable,
 
 uint32_t TlclSetGlobalLock(void)
 {
-	uint32_t x;
+	uint32_t x = 0;
 	VB2_DEBUG("TPM: Set global lock\n");
 	return TlclWrite(TPM_NV_INDEX0, (uint8_t*) &x, 0);
 }
