drm/amd/ras: Fix UMC error address allocation leak

drm/amd/ras: Fix UMC error address allocation leak

amdgpu_umc_handle_bad_pages() allocates err_data->err_addr before
querying UMC error information. In the direct and firmware query paths,
the pointer is reassigned to a fresh allocation before the original
buffer is released, so the initial allocation is leaked on each handled
event.

Free the existing buffer before replacing it in those query paths so the
function exit cleanup only owns the active allocation.

Signed-off-by: Xiang Liu <xiang.liu@amd.com>
Reviewed-by: Stanley.Yang <Stanley.Yang@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>