all: fix some symbols error in comment

Change-Id: If4bd2e8cd8dded33d434f4b60217fa46fcf5e934
Reviewed-on: https://go-review.googlesource.com/c/tools/+/611796
Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: shuang cui <imcusg@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Zvonimir Pavlinovic <zpavlinovic@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>

go/callgraph/vta/vta.go

@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package vta computes the call graph of a Go program using the Variable
-// Type Analysis (VTA) algorithm originally described in “Practical Virtual
+// Type Analysis (VTA) algorithm originally described in "Practical Virtual
 // Method Call Resolution for Java," Vijay Sundaresan, Laurie Hendren,
 // Chrislain Razafimahefa, Raja Vallée-Rai, Patrick Lam, Etienne Gagnon, and
 // Charles Godin.

go/packages/external.go

@@ -82,7 +82,7 @@ type DriverResponse struct {
 type driver func(cfg *Config, patterns ...string) (*DriverResponse, error)
 
 // findExternalDriver returns the file path of a tool that supplies
-// the build system package structure, or "" if not found."
+// the build system package structure, or "" if not found.
 // If GOPACKAGESDRIVER is set in the environment findExternalTool returns its
 // value, otherwise it searches for a binary named gopackagesdriver on the PATH.
 func findExternalDriver(cfg *Config) driver {

gopls/internal/vulncheck/vulntest/db.go

@@ -51,7 +51,7 @@ func NewDatabase(ctx context.Context, txtarReports []byte) (*DB, error) {
 
 // DB is a read-only vulnerability database on disk.
 // Users can use this database with golang.org/x/vuln APIs
-// by setting the `VULNDB“ environment variable.
+// by setting the `VULNDB` environment variable.
 type DB struct {
 	disk string
 }

internal/tool/tool.go

@@ -29,7 +29,7 @@ import (
 //       (&Application{}).Main("myapp", "non-flag-command-line-arg-help", os.Args[1:])
 //     }
 // It recursively scans the application object for fields with a tag containing
-//     `flag:"flagnames" help:"short help text"``
+//     `flag:"flagnames" help:"short help text"`
 // uses all those fields to build command line flags. It will split flagnames on
 // commas and add a flag per name.
 // It expects the Application type to have a method