Remove amdgpu_reference_drm_fd

Increase pAMDGPUEnt->fd_ref in the probe code instead when we're reusing
the existing fd.

The previous reference counting was imbalanced, so pAMDGPUEnt->fd_ref
could never go to 0.
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

src/amdgpu_kms.c

@@ -624,13 +624,6 @@ static Bool AMDGPUPreInitChipType_KMS(ScrnInfoPtr pScrn)
 	return TRUE;
 }
 
-static void amdgpu_reference_drm_fd(ScrnInfoPtr pScrn)
-{
-	AMDGPUEntPtr pAMDGPUEnt = AMDGPUEntPriv(pScrn);
-
-	pAMDGPUEnt->fd_ref++;
-}
-
 static Bool amdgpu_get_tile_config(ScrnInfoPtr pScrn)
 {
 	AMDGPUInfoPtr info = AMDGPUPTR(pScrn);
@@ -767,8 +760,6 @@ Bool AMDGPUPreInit_KMS(ScrnInfoPtr pScrn, int flags)
 	if (!AMDGPUPreInitChipType_KMS(pScrn))
 		goto fail;
 
-	amdgpu_reference_drm_fd(pScrn);
-
 	info->dri2.available = FALSE;
 	info->dri2.enabled = FALSE;
 	info->dri2.pKernelDRMVersion = drmGetVersion(pAMDGPUEnt->fd);

src/amdgpu_probe.c

@@ -245,6 +245,7 @@ static Bool amdgpu_get_scrninfo(int entity_num, struct pci_device *pci_dev)
 		}
 	} else {
 		pAMDGPUEnt = pPriv->ptr;
+		pAMDGPUEnt->fd_ref++;
 	}
 
 	xf86SetEntityInstanceForScreen(pScrn, pEnt->index,
@@ -360,6 +361,7 @@ amdgpu_platform_probe(DriverPtr pDriver,
 		}
 	} else {
 		pAMDGPUEnt = pPriv->ptr;
+		pAMDGPUEnt->fd_ref++;
 	}
 	pAMDGPUEnt->platform_dev = dev;