Starting with glibc 2.35, the mallinfo library call has finally been
upgraded to return 64-bit memory usage quantities. Migrate to the new
call, since it also warns about mallinfo being deprecated.
Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Eric Sandeen <sandeen@sandeen.net>