util: add doc comments for exported functions in errors.go

A number of exported functions in errors.go were missing doc comments.
Add them.

Signed-off-by: John Mulligan <[email protected]>

internal/util/errors.go

@@ -22,10 +22,12 @@ type ErrKeyNotFound struct {
 	err     error
 }
 
+// NewErrKeyNotFound returns a new ErrKeyNotFound error.
 func NewErrKeyNotFound(keyName string, err error) ErrKeyNotFound {
 	return ErrKeyNotFound{keyName, err}
 }
 
+// Error returns the error string for ErrKeyNotFound.
 func (e ErrKeyNotFound) Error() string {
 	return e.err.Error()
 }
@@ -36,6 +38,7 @@ type ErrObjectExists struct {
 	err        error
 }
 
+// Error returns the error string for ErrObjectExists.
 func (e ErrObjectExists) Error() string {
 	return e.err.Error()
 }
@@ -46,6 +49,7 @@ type ErrObjectNotFound struct {
 	err      error
 }
 
+// Error returns the error string for ErrObjectNotFound.
 func (e ErrObjectNotFound) Error() string {
 	return e.err.Error()
 }
@@ -57,6 +61,7 @@ type ErrSnapNameConflict struct {
 	err         error
 }
 
+// Error returns the error string for ErrSnapNameConflict.
 func (e ErrSnapNameConflict) Error() string {
 	return e.err.Error()
 }
@@ -72,10 +77,12 @@ type ErrPoolNotFound struct {
 	Err  error
 }
 
+// Error returns the error string for ErrPoolNotFound.
 func (e ErrPoolNotFound) Error() string {
 	return e.Err.Error()
 }
 
+// NewErrPoolNotFound returns a new ErrPoolNotFound error.
 func NewErrPoolNotFound(pool string, err error) ErrPoolNotFound {
 	return ErrPoolNotFound{pool, err}
 }