I heard of this rumor in the comments of a YouTube video, but searching for it brings me only to a tumblr post and some meme pages. But I do want it to be true. Especially since it reminds me that no matter how far ago people lived, they were still people. And it made me think; while I have heard about crass Roman graffiti, was this a common thing for Vikings too?
Perhaps you're thinking of the Maeshowes runes on the Orkney Islands. They were craved by a few drunken Danish crusaders around the 12th century.
Being drunk you can imagine they weren't carving anything important. One reads, "Tholfir Kolbeinsson carved these runes very high up." This may be the one you're thinking of.
Was it common for Vikings? Yes. Were a lot of them humorous? Oh, yes. Among the rune I had mentioned were countless "______ carved these runes", essentially ____ was here. My favorite being, "These runes were carved by the man most skilled in runes in the western ocean."
This is a common trait amongst Nordic runes and can be found anywhere they traveled from Sicily to Turkey.