mm: make !CONFIG_HUGE_PAGE wrappers into static inlines

Instead of using defines, which loses type safety and provokes unused
variable warnings from gcc, put the constants into static inlines.

Link: http://lkml.kernel.org/r/20190522235102.GA15370@mellanox.com


Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>