The ornamental design for a fasteningdevice, as shown and described.
FIG. 1 is a front perspective view of a first embodiment of the invention.
FIG. 2 is a top plan view of FIG. 1.
FIG. 3 is a front elevation view of FIG. 1.
FIG. 4 is a right side elevation view of FIG. 1.
FIG. 5 is a left side elevation view of FIG. 1.
FIG. 6 is a rear elevation view of FIG. 1.
FIG. 7 is a bottom plan view of FIG. 1.
FIG. 8 is a front perspective view of a second embodiment of the invention.
FIG. 9 is a top plan view of FIG. 8.
FIG. 10 is a front elevation view of FIG. 8.
FIG. 11 is a left side elevation view of FIG. 8.
FIG. 12 is a right side elevation view of FIG. 8.
FIG. 13 is a rear plan view of FIG. 8; and,
FIG. 14. is a bottom reversed plan view of FIG. 8.
The broken lines in the figures represent areas of the fastening device that form no part of the claimed design. The dash-dot-dash lines in the figures represent boundaries between claimed and unclaimed field areas, e.g., the field-break lines in FIG. 1 noting no claim beyond the end-portion. Shading lines are provided as illustrative aids only, and no claim is made to a surface texture.