The ornamental design for a U-lock spacer barrier, as shown and described.
FIG. 1 is a top, front, and right side perspective view of a U-lock spacer
barrier showing my new design, the broken-line disclosure of a portion of
a bicycle, post, and U-lock being for illustrative purposes only and
forming no part of the claimed design;
FIG. 2 is an enlarged top, front, and right side elevational view thereof;
FIG. 3 is an enlarged top plan view thereof, the bottom being identical in
appearance;
FIG. 4 is an enlarged front elevational view thereof, the rear being
identical in appearance; and,
FIG. 5 is an enlarged side elevational view thereof, the opposite side
being identical in appearance.