x86: remove dummy long from EFI stub

Commit 2e064b1e (x86, efi: Fix issue of overlapping .reloc section for
EFI_STUB) removed a dummy reloc added by commit 291f3632

 (x86, efi: EFI
boot stub support), but forgot to remove the dummy long used by that
reloc.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Lee G Rosenbaum <lee.g.rosenbaum@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>