drm/xe/exec: Fix minor bug related to xe_sync_entry_cleanup

Increment num_syncs after xe_sync_entry_parse() is successful to ensure
the xe_sync_entry_cleanup() logic under "err_syncs" label works correctly.

v2: Use the same pattern as that in xe_vm.c (Matt Brost)

Fixes: dd08ebf ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240711211203.3728180-1-ashutosh.dixit@intel.com
(cherry picked from commit 43a6faa)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_exec.c

@@ -118,7 +118,7 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	u64 addresses[XE_HW_ENGINE_MAX_INSTANCE];
 	struct drm_gpuvm_exec vm_exec = {.extra.fn = xe_exec_fn};
 	struct drm_exec *exec = &vm_exec.exec;
-	u32 i, num_syncs = 0, num_ufence = 0;
+	u32 i, num_syncs, num_ufence = 0;
 	struct xe_sched_job *job;
 	struct xe_vm *vm;
 	bool write_locked, skip_retry = false;
@@ -156,15 +156,15 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 
 	vm = q->vm;
 
-	for (i = 0; i < args->num_syncs; i++) {
-		err = xe_sync_entry_parse(xe, xef, &syncs[num_syncs++],
-					  &syncs_user[i], SYNC_PARSE_FLAG_EXEC |
+	for (num_syncs = 0; num_syncs < args->num_syncs; num_syncs++) {
+		err = xe_sync_entry_parse(xe, xef, &syncs[num_syncs],
+					  &syncs_user[num_syncs], SYNC_PARSE_FLAG_EXEC |
 					  (xe_vm_in_lr_mode(vm) ?
 					   SYNC_PARSE_FLAG_LR_MODE : 0));
 		if (err)
 			goto err_syncs;
 
-		if (xe_sync_is_ufence(&syncs[i]))
+		if (xe_sync_is_ufence(&syncs[num_syncs]))
 			num_ufence++;
 	}
 
@@ -325,8 +325,8 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	if (err == -EAGAIN && !skip_retry)
 		goto retry;
 err_syncs:
-	for (i = 0; i < num_syncs; i++)
-		xe_sync_entry_cleanup(&syncs[i]);
+	while (num_syncs--)
+		xe_sync_entry_cleanup(&syncs[num_syncs]);
 	kfree(syncs);
 err_exec_queue:
 	xe_exec_queue_put(q);