The ornamental design for an coverall, as shown and described.
FIG. 1 is a front perspective view of a coverall showing my new design.
FIG. 2 is another front perspective view thereof.
FIG. 3 is a rear perspective view thereof.
FIG. 4 is a front view thereof.
FIG. 5 is a back view thereof.
FIG. 6 is a left side view thereof.
FIG. 7 is a right side view thereof; and,
FIG. 8 is a front view thereof, showing the outdoor activity suit unzipped.
The dot-dash broken lines in FIGS. 1, 2, 4 and 8 represent the boundaries of the design and form no part of the claim. The evenly spaced broken lines in FIGS. 4 and 8 represent unclaimed portions of the design.