hugetlbfs: convert macros to static inline, fix sparse warning

hugetlbfs: convert macros to static inline, fix sparse warning

huge_pte_offset() produced a sparse warning due to an improper return
type when the kernel was built with !CONFIG_HUGETLB_PAGE.  Fix the bad
type and also convert all the macros in this block to static inline
wrappers.  Two existing wrappers in this block had lines in excess of 80
columns so clean those up as well.

No functional change.

Link: http://lkml.kernel.org/r/20191112194558.139389-3-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Ben Dooks <ben.dooks@codethink.co.uk>
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>