The ornamental design for a fishingrodholder, as shown and described.
FIG. 1 is a top perspective view of a fishing rod holder;
FIG. 2 is a left-side view thereof;
FIG. 3 is a right-side view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The dashed broken lines depict portions of the fishing rod holder that form no part of the claimed design. The dot-dashed broken lines represent boundaries of the claimed fishing rod holder and form no part of the claimed design.