drm/gpusvm: set has_dma_mapping inside mapping loop

The 'has_dma_mapping' flag should be set once there is a
mapping so it could be unmapped in case of error.

v2:
- Resend for CI

Fixes: 99624bd ("drm/gpusvm: Add support for GPU Shared Virtual Memory")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250428024752.881292-1-matthew.brost@intel.com
(cherry picked from commit f64cf7b)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Author: dhirschfeld1

drivers/gpu/drm/drm_gpusvm.c

@@ -1469,9 +1469,9 @@ int drm_gpusvm_range_get_pages(struct drm_gpusvm *gpusvm,
 		}
 		i += 1 << order;
 		num_dma_mapped = i;
+		range->flags.has_dma_mapping = true;
 	}
 
-	range->flags.has_dma_mapping = true;
 	if (zdd) {
 		range->flags.has_devmem_pages = true;
 		range->dpagemap = dpagemap;