* include/grub/dl.h (grub_dl_check_header): New prototype.
(grub_arch_dl_check_header): Change return type to grub_err_t,
remove size parameter and export function. Update all callers.
* kern/dl.c (grub_dl_check_header): New function.
(grub_dl_load_core): Use `grub_dl_check_header' instead of
`grub_arch_dl_check_header'. Check ELF type. Check if sections
are inside the core.
* kern/i386/dl.c (grub_arch_dl_check_header): Remove arch
independent ELF header checks.
* kern/powerpc/dl.c (grub_arch_dl_check_header): Likewise.
* loader/i386/pc/multiboot.c (grub_rescue_cmd_multiboot): Use
`grub_dl_check_header' instead of explicit checks. Check for the
ELF type.
* loader/powerpc/ieee1275/linux.c (grub_rescue_cmd_linux): Use
`grub_dl_check_header' instead of explicit checks. Remove arch
specific ELF header checks.