The ornamental design for a suctiongrabbar, as shown and described.
FIG. 1 is a front perspective view of a suction grab bar in accordance with the present invention;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a bottom perspective view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a front elevational view thereof;
FIG. 6 is a right side elevational view thereof, the left side elevational view being a mirror image of the right side elevational view;
FIG. 7 is a rear elevational view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown in the Figures are included for the purpose of illustrating portions of the suction grab bar which form no part of the claimed design.