error: redefinition of ‘dax_supported’

[Nick Desaulniers]

Hello DAX maintainers,
I noticed our PPC64LE builds failing last night:
https://travis-ci.com/github/ClangBuiltLinux/continuous-integration/jobs/388047043
https://travis-ci.com/github/ClangBuiltLinux/continuous-integration/jobs/388047056
https://travis-ci.com/github/ClangBuiltLinux/continuous-integration/jobs/388047099
and looking on lore, I see a fresh report from KernelCI against arm:
https://lore.kernel.org/linux-next/?q=dax_supported

Can you all please take a look?  More concerning is that I see this
failure on mainline.  It may be interesting to consider how this was
not spotted on -next.
-- 
Thanks,
~Nick Desaulniers