The ornamental design for a coffeepot, as shown and described.
1. Coffee pot
1.1: Perspective
1.2: Perspective
1.3: Front
1.4: Back
1.5: Left
1.6: Right
1.7: Top
1.8: Bottom
Reproduction 1.1is a front perspective view; reproduction 1.2is a back perspective view; reproduction 1.3is a front view; reproduction 1.4is a back view; reproduction 1.5is a left view; reproduction 1.6is a right view; reproduction 1.7is a top view; and reproduction 1.8is a bottom view. The dashed broken lines in the reproductions represent portions of the coffee pot that form no part of the claimed design.