MISRA fix: Use boolean essential type

Change the return type of "arm_io_is_toc_valid()" and
"plat_arm_bl1_fwu_needed()" to bool, to match function behavior.

Change-Id: I503fba211219a241cb263149ef36ca14e3362a1c
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
diff --git a/plat/arm/board/juno/juno_bl1_setup.c b/plat/arm/board/juno/juno_bl1_setup.c
index 89398d6..25a27da 100644
--- a/plat/arm/board/juno/juno_bl1_setup.c
+++ b/plat/arm/board/juno/juno_bl1_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -60,17 +60,13 @@
  * The following function checks if Firmware update is needed,
  * by checking if TOC in FIP image is valid or watchdog reset happened.
  ******************************************************************************/
-int plat_arm_bl1_fwu_needed(void)
+bool plat_arm_bl1_fwu_needed(void)
 {
 	const int32_t *nv_flags_ptr = (const int32_t *)V2M_SYS_NVFLAGS_ADDR;
 
 	/* Check if TOC is invalid or watchdog reset happened. */
-	if ((arm_io_is_toc_valid() != 1) ||
-		(((*nv_flags_ptr == -EAUTH) || (*nv_flags_ptr == -ENOENT))
-		&& is_watchdog_reset()))
-		return 1;
-
-	return 0;
+	return (!arm_io_is_toc_valid() || (((*nv_flags_ptr == -EAUTH) ||
+		(*nv_flags_ptr == -ENOENT)) && is_watchdog_reset()));
 }
 
 /*******************************************************************************
diff --git a/plat/arm/common/arm_bl1_setup.c b/plat/arm/common/arm_bl1_setup.c
index bf4d7bd..c2f49c2 100644
--- a/plat/arm/common/arm_bl1_setup.c
+++ b/plat/arm/common/arm_bl1_setup.c
@@ -188,9 +188,9 @@
  * On Arm platforms, the FWU process is triggered when the FIP image has
  * been tampered with.
  */
-int plat_arm_bl1_fwu_needed(void)
+bool plat_arm_bl1_fwu_needed(void)
 {
-	return (arm_io_is_toc_valid() != 1);
+	return !arm_io_is_toc_valid();
 }
 
 /*******************************************************************************
@@ -199,8 +199,5 @@
  ******************************************************************************/
 unsigned int bl1_plat_get_next_image_id(void)
 {
-	if (plat_arm_bl1_fwu_needed() != 0)
-		return NS_BL1U_IMAGE_ID;
-
-	return BL2_IMAGE_ID;
+	return plat_arm_bl1_fwu_needed() ? NS_BL1U_IMAGE_ID : BL2_IMAGE_ID;
 }
diff --git a/plat/arm/common/arm_fconf_io_storage.c b/plat/arm/common/arm_fconf_io_storage.c
index afc8dbe..6bbdb3c 100644
--- a/plat/arm/common/arm_fconf_io_storage.c
+++ b/plat/arm/common/arm_fconf_io_storage.c
@@ -128,15 +128,7 @@
  * See if a Firmware Image Package is available,
  * by checking if TOC is valid or not.
  */
-int arm_io_is_toc_valid(void)
+bool arm_io_is_toc_valid(void)
 {
-	int result;
-
-	result = io_dev_init(fip_dev_handle, (uintptr_t)FIP_IMAGE_ID);
-
-	if (result == 0) {
-		return 1UL;
-	} else {
-		return 0UL;
-	}
+	return (io_dev_init(fip_dev_handle, (uintptr_t)FIP_IMAGE_ID) == 0);
 }
diff --git a/plat/arm/common/arm_io_storage.c b/plat/arm/common/arm_io_storage.c
index fc1eb49..60d19b2 100644
--- a/plat/arm/common/arm_io_storage.c
+++ b/plat/arm/common/arm_io_storage.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -357,12 +357,8 @@
  * See if a Firmware Image Package is available,
  * by checking if TOC is valid or not.
  */
-int arm_io_is_toc_valid(void)
+bool arm_io_is_toc_valid(void)
 {
-	int result;
-
-	result = io_dev_init(fip_dev_handle, (uintptr_t)FIP_IMAGE_ID);
-
-	return (result == 0);
+	return (io_dev_init(fip_dev_handle, (uintptr_t)FIP_IMAGE_ID) == 0);
 }