[ Upstream commit 2cbade17b18c0f0fd9963f26c9fc9b057eb1cb3a ]
The __switch_mm function is defined in the user code, and is called
by the kernel code. It should be declared in a shared header.
Fixes: 4dc706c2f292 ("um: take um_mmu.h to asm/mmu.h, clean asm/mmu_context.h a bit")
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
