elf-loader: warn about invalid endianness

fprintf(stderr) is how errors are reported in this file.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/core/loader.c

@@ -478,6 +478,7 @@ int load_elf_ram(const char *filename,
     }
 
     if (target_data_order != e_ident[EI_DATA]) {
+        fprintf(stderr, "%s: wrong endianness\n", filename);
         ret = ELF_LOAD_WRONG_ENDIAN;
         goto fail;
     }