efi: Fix debugobjects warning on 'efi_rts_work'

The following commit:

  9dbbedaa

 ("efi: Make efi_rts_work accessible to efi page fault handler")

converted 'efi_rts_work' from an auto variable to a global variable.
However, when submitting the work, INIT_WORK_ONSTACK() was still used,
causing the following complaint from debugobjects:

  ODEBUG: object 00000000ed27b500 is NOT on stack 00000000c7d38760, but annotated.

Change the macro to just INIT_WORK() to eliminate the warning.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 9dbbedaa

 ("efi: Make efi_rts_work accessible to efi page fault handler")
Link: http://lkml.kernel.org/r/20181114175544.12860-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>