Check error return from bfd_canonicalize_dynamic_reloc
    
    Since bfd_canonicalize_dynamic_reloc returns -1 on error, check it in
    _bfd_x86_elf_get_synthetic_symtab.
    
    	PR ld/22148
    	* elfxx-x86.c (_bfd_x86_elf_get_synthetic_symtab): Check error
    	return from bfd_canonicalize_dynamic_reloc.