drm/amd/display: remove redundant null check of array 'data'

The null check on aconnector->base.edid_blob_ptr->data is redundant
since data is an array and can never be null.  Remove it.

Detected by CoverityScan, CID#1460369 ("Array compared against 0")

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>