acpi/nfit: Use sysfs_emit() for all attributes

acpi/nfit: Use sysfs_emit() for all attributes

sysfs_emit() properly handles the PAGE_SIZE limitation of populating
sysfs attribute buffers. Clean up the deprecated usage of sprintf() in
all of nfit's sysfs show() handlers.

Reported-by: Ben Dooks <ben.dooks@codethink.co.uk>
Closes: http://lore.kernel.org/0d1bf461-d9e8-88bc-b7e2-b03b56594213@codethink.co.uk
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/170303851337.2238503.5103082574938957743.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>