errdefs: remove redundant import comments

A package only needs one "import" comment to enforce, so keeping
one in the go.doc.

It should be noted that even with that; in most cases, go will ignore
these comments (if go modules are used, even in "vendor" mode).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

errdefs/defs.go

@@ -1,4 +1,4 @@
-package errdefs // import "github.com/docker/docker/errdefs"
+package errdefs
 
 // ErrNotFound signals that the requested object doesn't exist
 type ErrNotFound interface {

errdefs/helpers.go

@@ -1,4 +1,4 @@
-package errdefs // import "github.com/docker/docker/errdefs"
+package errdefs
 
 import "context"
 

errdefs/helpers_test.go

@@ -1,4 +1,4 @@
-package errdefs // import "github.com/docker/docker/errdefs"
+package errdefs
 
 import (
 	"errors"

errdefs/http_helpers.go

@@ -1,4 +1,4 @@
-package errdefs // import "github.com/docker/docker/errdefs"
+package errdefs
 
 import (
 	"net/http"

errdefs/is.go

@@ -1,4 +1,4 @@
-package errdefs // import "github.com/docker/docker/errdefs"
+package errdefs
 
 type causer interface {
 	Cause() error