powerpc/vdso: refactor error handling

Linus noticed that the error handling in __arch_setup_additional_pages()
fails to clear the mm VDSO pointer if _install_special_mapping() fails. 
In practice there should be no actual bug, because if there's an error the
VDSO pointer is cleared later in arch_setup_additional_pages().

However it's no longer necessary to set the pointer before installing the
mapping.  Commit c1bab64360e6 ("powerpc/vdso: Move to
_install_special_mapping() and remove arch_vma_name()") reworked the code
so that the VMA name comes from the vm_special_mapping.name, rather than
relying on arch_vma_name().

So rework the code to only set the VDSO pointer once the mappings have
been installed correctly, and remove the stale comment.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Michael Ellerman <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Jeff Xu <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions