selftests/mm: FOLL_LONGTERM need to be updated to 0x100

After commit 2c224108 ("mm/gup: move private gup FOLL_ flags to
internal.h") FOLL_LONGTERM flag value got updated from 0x10000 to 0x100 at
include/linux/mm_types.h.

As hmm.hmm_device_private.hmm_gup_test uses FOLL_LONGTERM Updating same
here as well.

Before this change test goes in an infinite assert loop in
hmm.hmm_device_private.hmm_gup_test
==========================================================
 RUN           hmm.hmm_device_private.hmm_gup_test ...
hmm-tests.c:1962:hmm_gup_test:Expected HMM_DMIRROR_PROT_WRITE..
..(2) == m[2] (34)
hmm-tests.c:157:hmm_gup_test:Expected ret (-1) == 0 (0)
hmm-tests.c:157:hmm_gup_test:Expected ret (-1) == 0 (0)
...
==========================================================

 Call Trace:
 <TASK>
 ? sched_clock+0xd/0x20
 ? __lock_acquire.constprop.0+0x120/0x6c0
 ? ktime_get+0x2c/0xd0
 ? sched_clock+0xd/0x20
 ? local_clock+0x12/0xd0
 ? lock_release+0x26e/0x3b0
 pin_user_pages_fast+0x4c/0x70
 gup_test_ioctl+0x4ff/0xbb0
 ? gup_test_ioctl+0x68c/0xbb0
 __x64_sys_ioctl+0x99/0xd0
 do_syscall_64+0x60/0x90
 ? syscall_exit_to_user_mode+0x2a/0x50
 ? do_syscall_64+0x6d/0x90
 ? syscall_exit_to_user_mode+0x2a/0x50
 ? do_syscall_64+0x6d/0x90
 ? irqentry_exit_to_user_mode+0xd/0x20
 ? irqentry_exit+0x3f/0x50
 ? exc_page_fault+0x96/0x200
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
 RIP: 0033:0x7f6aaa31aaff

After this change test is able to pass successfully.

Link: https://lkml.kernel.org/r/20230808124347.79163-1-ayush.jain3@amd.com
Fixes: 2c224108

 ("mm/gup: move private gup FOLL_ flags to internal.h")
Signed-off-by: Ayush Jain <ayush.jain3@amd.com>
Reviewed-by: Raghavendra K T <raghavendra.kt@amd.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>