drm/msm/dpu: cleanup FB if dpu_format_populate_layout fails

In the Linux kernel, the following vulnerability has been resolved:

drm/msm/dpu: cleanup FB if dpu_format_populate_layout fails

If the dpu_format_populate_layout() fails, then FB is prepared, but not

cleaned up. This ends up leaking the pin_count on the GEM object and

causes a splat during DRM file closure:

msm_obj->pin_count

WARNING: CPU: 2 PID: 569 at drivers/gpu/drm/msm/msm_gem.c:121 update_lru_locked+0xc4/0xcc

[...]

Call trace:

update_lru_locked+0xc4/0xcc

put_pages+0xac/0x100

msm_gem_free_object+0x138/0x180

drm_gem_object_free+0x1c/0x30

drm_gem_object_handle_put_unlocked+0x108/0x10c

drm_gem_object_release_handle+0x58/0x70

idr_for_each+0x68/0xec

drm_gem_release+0x28/0x40

drm_file_free+0x174/0x234

drm_release+0xb0/0x160

__fput+0xc0/0x2c8

__fput_sync+0x50/0x5c

__arm64_sys_close+0x38/0x7c

invoke_syscall+0x48/0x118

el0_svc_common.constprop.0+0x40/0xe0

do_el0_svc+0x1c/0x28

el0_svc+0x4c/0x120

el0t_64_sync_handler+0x100/0x12c

el0t_64_sync+0x190/0x194

irq event stamp: 129818

hardirqs last enabled at (129817): [<ffffa5f6d953fcc0>] console_unlock+0x118/0x124

hardirqs last disabled at (129818): [<ffffa5f6da7dcf04>] el1_dbg+0x24/0x8c

softirqs last enabled at (129808): [<ffffa5f6d94afc18>] handle_softirqs+0x4c8/0x4e8

softirqs last disabled at (129785): [<ffffa5f6d94105e4>] __do_softirq+0x14/0x20

Patchwork: https://patchwork.freedesktop.org/patch/600714/