cmd/go: fix fmt.Errorf call sites (latent bug)

Change-Id: I4ff42113c5dda553d6f3d58f0e4836dce7c84710
Reviewed-on: https://go-review.googlesource.com/10730Reviewed-by: Rob Pike <r@golang.org>

src/cmd/go/note.go

@@ -57,23 +57,23 @@ func readnote(filename, name string, typ int32) ([]byte, error) {
 				if err == io.EOF {
 					break
 				}
-				return nil, fmt.Errorf("read namesize failed:", err)
+				return nil, fmt.Errorf("read namesize failed: %v", err)
 			}
 			err = binary.Read(r, f.ByteOrder, &descsize)
 			if err != nil {
-				return nil, fmt.Errorf("read descsize failed:", err)
+				return nil, fmt.Errorf("read descsize failed: %v", err)
 			}
 			err = binary.Read(r, f.ByteOrder, &noteType)
 			if err != nil {
-				return nil, fmt.Errorf("read type failed:", err)
+				return nil, fmt.Errorf("read type failed: %v", err)
 			}
 			noteName, err := readwithpad(r, namesize)
 			if err != nil {
-				return nil, fmt.Errorf("read name failed:", err)
+				return nil, fmt.Errorf("read name failed: %v", err)
 			}
 			desc, err := readwithpad(r, descsize)
 			if err != nil {
-				return nil, fmt.Errorf("read desc failed:", err)
+				return nil, fmt.Errorf("read desc failed: %v", err)
 			}
 			if name == string(noteName) && typ == noteType {
 				return desc, nil