The ornamental design for a smokingstraw, as shown and described.
FIG. 1 is a perspective view of a smoking straw, showing our new design;
FIG. 2 is an enlarged perspective view thereof, shown removed from environment for clarity of disclosure;
FIG. 3 is a front elevational view thereof, the rear elevational view, left-side elevational view, and right-side elevational view all being identical thereto;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a cross-sectional view thereof, taken along lines 6-6 of FIG. 4.
The broken lines showing a smoking pipe in FIG. 1 depict environmental matter and form no part of the claimed design.