drm/vkms: Fix color pipeline enum name leak

drm/vkms: Fix color pipeline enum name leak

vkms_initialize_colorops() allocates enum names for color pipelines,
which are copied by drm_property_create_enum(). The temporary strings
were not freed, resulting in a memory leak.

Allocate enum names only after successful pipeline construction and
free them on all exit paths

Fixes: c1e578bd08da ("drm/vkms: Add enumerated 1D curve colorop")
Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
Link: https://patch.msgid.link/20260113102303.724205-4-chaitanya.kumar.borah@intel.com