Fix Coverity #342970, Uninitialized scalar variable

This ensures that probe_data starts with a reasonable default, as
opposed to whatever was left on the stack.

Change-Id: I5550efea5e2bec7717f9fa063cb11e6a7005cce5
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>

lib/extensions/ras/ras_common.c

 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -83,7 +83,8 @@ static int ras_interrupt_handler(uint32_t intr_raw, uint32_t flags,
 {
 	struct ras_interrupt *ras_inrs = ras_interrupt_mappings.intrs;
 	struct ras_interrupt *selected = NULL;
-	int start, end, mid, probe_data, ret __unused;
+	int probe_data = 0;
+	int start, end, mid, ret __unused;
 
 	const struct err_handler_data err_data = {
 		.version = ERR_HANDLER_VERSION,