[PATCH next] drm/i915: Fix NULL vs IS_ERR() check in __shmem_writeback()

[Dan Carpenter]

The filemap_lock_folio() function doesn't return NULL, it returns error
pointers.

Fixes: 25dd342f0cc8 ("drm/i915/gem: convert __shmem_writeback() to folios")
Signed-off-by: Dan Carpenter <dan.carpen...@linaro.org>
---
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c 
b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index a784fb44e59c..fb263b421958 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -319,7 +319,7 @@ void __shmem_writeback(size_t size, struct address_space 
*mapping)
                struct folio *folio;
 
                folio = filemap_lock_folio(mapping, i);
-               if (!folio)
+               if (IS_ERR(folio))
                        continue;
 
                if (!folio_mapped(folio) && folio_clear_dirty_for_io(folio)) {
-- 
2.47.2