drm/i915/gvt: fix an issue in emulating cfg space PCI_COMMAND

There's an issue in current cfg space emulation for PCI_COMMAND (offset
0x4): when guest changes some bits other than PCI_COMMAND_MEMORY, this
write operation will not be written to virutal cfg space successfully.

This patch is to fix the wrong behavior above.
Signed-off-by: Min He <min.he@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/cfg_space.c

@@ -123,6 +123,7 @@ static int emulate_pci_command_write(struct intel_vgpu *vgpu,
 	u8 changed = old ^ new;
 	int ret;
 
+	memcpy(vgpu_cfg_space(vgpu) + offset, p_data, bytes);
 	if (!(changed & PCI_COMMAND_MEMORY))
 		return 0;
 
@@ -142,7 +143,6 @@ static int emulate_pci_command_write(struct intel_vgpu *vgpu,
 			return ret;
 	}
 
-	memcpy(vgpu_cfg_space(vgpu) + offset, p_data, bytes);
 	return 0;
 }