sparc64: DAX request to mmap non 4MB memory should fail with a debug print

sparc64: DAX request to mmap non 4MB memory should fail with a debug print

Orabug:25852910

When the dax flow control is disabled, dax_alloc_mem(...) only allows 4MB
allocation in the driver. Any other requests are reported as an error
with an error print to the kernel log. We now have a dax subpage
allocator in libdax which gets triggered when the driver reports the
above said failure. In other words it is a normal use case for the driver
to report this. So make this a debug print.

Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: Sanath Kumar <sanath.s.kumar@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>