hugetlb: remove unused variable warning

Remove the following warning when CONFIG_HUGETLB_PAGE is not set:

	ipc/shm.c: In function `shm_get_stat':
	ipc/shm.c:565: warning: unused variable `h'

[akpm@linux-foundation.org: use tabs, not spaces]
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>