elf: Don't match corrupt section header in linker input

Don't swap in nor match corrupt section header in linker input to avoid
linker crash later.

	PR ld/33457
	* elfcode.h (elf_swap_shdr_in): Changed to return bool.  Return
	false for corrupt section header in linker input.
	(elf_object_p): Reject if elf_swap_shdr_in returns false.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>