hw/arm/boot: Report error msg if loading elf/dtb failed

Print errors before exit. Do not exit silently.

Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240903133940.3447430-1-changbin.du@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/boot.c

@@ -839,6 +839,8 @@ static ssize_t arm_load_elf(struct arm_boot_info *info, uint64_t *pentry,
                       1, data_swab, as);
     if (ret <= 0) {
         /* The header loaded but the image didn't */
+        error_report("Couldn't load elf '%s': %s",
+                     info->kernel_filename, load_elf_strerror(ret));
         exit(1);
     }