MAINTAINERS: fix Xinhui's name

Switch to fist last for consistency.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Xinhui Pan <Xinhui.Pan@amd.com>

MAINTAINERS

@@ -18656,7 +18656,7 @@ F:	drivers/net/wireless/quantenna
 RADEON and AMDGPU DRM DRIVERS
 M:	Alex Deucher <alexander.deucher@amd.com>
 M:	Christian König <christian.koenig@amd.com>
-M:	Pan, Xinhui <Xinhui.Pan@amd.com>
+M:	Xinhui Pan <Xinhui.Pan@amd.com>
 L:	amd-gfx@lists.freedesktop.org
 S:	Supported
 B:	https://gitlab.freedesktop.org/drm/amd/-/issues