drm: Match sysfs name in link removal to link creation

This patch matches the sysfs name used in the unlinking with the
linking function. Otherwise, remove_compat_control_link() fails to remove
sysfs created by create_compat_control_link() in drm_dev_register().

Fixes: 6449b088

 ("drm: Add fake controlD* symlinks for backwards
compat")
Cc: Dave Airlie <airlied@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[seanpaul added Fixes and Cc tags]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180511041542.GA4253@haneen-vb