arm64/efi: Don't fail check current_in_efi() if preemptible

arm64/efi: Don't fail check current_in_efi() if preemptible

As EFI runtime services can now be run without disabling preemption remove
the check for non preemptible in current_in_efi(). Without this change,
firmware errors that were previously recovered from by
__efi_runtime_kernel_fixup_exception() will lead to a kernel oops.

Fixes: a5baf582f4c0 ("arm64/efi: Call EFI runtime services without disabling preemption")
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Richard Lyu <richard.lyu@suse.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>