cmd/distpack: add fix tool to inventory

(To be consistent with change to build.go in CL 700795.)

For golang#71859

Change-Id: I8caad28b7e5a2657f21b60a72899daecf0b2c324
Reviewed-on: https://go-review.googlesource.com/c/go/+/712180
Auto-Submit: Alan Donovan <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>
TryBot-Bypass: Alan Donovan <[email protected]>

Author: adonovan

src/cmd/distpack/pack.go

@@ -172,7 +172,7 @@ func main() {
 			default:
 				return false
 			// Keep in sync with toolsIncludedInDistpack in cmd/dist/build.go.
-			case "asm", "cgo", "compile", "cover", "link", "preprofile", "vet":
+			case "asm", "cgo", "compile", "cover", "fix", "link", "preprofile", "vet":
 			}
 		}
 		return true