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: a5baf58 ("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>

Author: benhor01

arch/arm64/include/asm/efi.h

@@ -45,7 +45,7 @@ void arch_efi_call_virt_teardown(void);
  * switching to the EFI runtime stack.
  */
 #define current_in_efi()						\
-	(!preemptible() && efi_rt_stack_top != NULL &&			\
+	(efi_rt_stack_top != NULL &&					\
 	 on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1))
 
 #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)