go.mod: bump x/tools

Fixes #2912 (which had rebase issues)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

go.mod

@@ -44,7 +44,7 @@ require (
 	golang.org/x/sys v0.0.0-20210906170528-6f6e22806c34
 	golang.org/x/term v0.0.0-20210503060354-a79de5458b56
 	golang.org/x/time v0.0.0-20210611083556-38a9dc6acbc6
-	golang.org/x/tools v0.1.2
+	golang.org/x/tools v0.1.6
 	golang.zx2c4.com/wireguard v0.0.0-20210905140043-2ef39d47540c
 	golang.zx2c4.com/wireguard/windows v0.4.9
 	honnef.co/go/tools v0.2.1

go.sum

@@ -879,6 +879,8 @@ golang.org/x/tools v0.0.0-20201211185031-d93e913c1a58/go.mod h1:emZCQorbCU4vsT4f
 golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
 golang.org/x/tools v0.1.2 h1:kRBLX7v7Af8W7Gdbbc908OJcdgtK8bOz9Uaj8/F1ACA=
 golang.org/x/tools v0.1.2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/tools v0.1.6 h1:SIasE1FVIQOWz2GEAHFOmoW7xchJcqlucjSULTL0Ag4=
+golang.org/x/tools v0.1.6/go.mod h1:LGqMHiF4EqQNHR1JncWGqT5BVaXmza+X+BDGol+dOxo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=