vboot/ui/tests: Fix struct compare error in unit tests

Use packed structures to avoid unexpected error about padding.

BUG=b:156448738, b:170186754
BRANCH=none
TEST=CC=x86_64-pc-linux-gnu-clang;
     make clean && make runtests
TEST=FEATURES=test PKGDIR=/build/puff/test-packages
     /mnt/host/source/chromite/bin/parallel_emerge
     --sysroot=/build/puff --jobs=32 vboot_reference

Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
Change-Id: Ibdcffe81d92db2880c53282a313ffa678af7d43d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2454911
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
diff --git a/tests/vb2_ui_action_tests.c b/tests/vb2_ui_action_tests.c
index 79f82ca..e439d91 100644
--- a/tests/vb2_ui_action_tests.c
+++ b/tests/vb2_ui_action_tests.c
@@ -33,7 +33,7 @@
 	uint32_t locale_id;
 	uint32_t selected_item;
 	uint32_t disabled_item_mask;
-};
+} __attribute__((packed));
 
 static uint8_t workbuf[VB2_KERNEL_WORKBUF_RECOMMENDED_SIZE]
 	__attribute__((aligned(VB2_WORKBUF_ALIGN)));
diff --git a/tests/vb2_ui_tests.c b/tests/vb2_ui_tests.c
index 5dc1a2e..004836a 100644
--- a/tests/vb2_ui_tests.c
+++ b/tests/vb2_ui_tests.c
@@ -29,7 +29,7 @@
 	uint32_t disabled_item_mask;
 	/* TODO(b/156448738): Add more params and their tests */
 	uint32_t current_page;
-};
+} __attribute__((packed));
 
 struct beep_call {
 	uint32_t msec;