The ornamental design for a foldingmat, as shown and described.
FIG. 1 is a front, left and top perspective view of a folding mat, showing my design.
FIG. 2 is a rear, right and bottom perspective view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a right side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged view of an area labeled 9 in FIG. 1.
The broken lines depict portions of the folding mat that form no part of the claimed design. The dot-dash broken lines in FIGS. 1 and 9 depict the boundaries of the enlargements that form no part of the claimed design.