editions: Fix spelling mistake in panic message

Fixed a little spelling mistake in this file that I noticed while
running lintian on a .deb I built for a utility I was working on that
uses this library.

Change-Id: I6c6a0da9960a07a8dccd2af3588530ff4e24809c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/697595
Auto-Submit: Lasse Folger <lassefolger@google.com>
Reviewed-by: Lasse Folger <lassefolger@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
diff --git a/internal/filedesc/editions.go b/internal/filedesc/editions.go
index a0aad27..66ba906 100644
--- a/internal/filedesc/editions.go
+++ b/internal/filedesc/editions.go
@@ -13,8 +13,10 @@
 	"google.golang.org/protobuf/reflect/protoreflect"
 )
 
-var defaultsCache = make(map[Edition]EditionFeatures)
-var defaultsKeys = []Edition{}
+var (
+	defaultsCache = make(map[Edition]EditionFeatures)
+	defaultsKeys  = []Edition{}
+)
 
 func init() {
 	unmarshalEditionDefaults(editiondefaults.Defaults)
@@ -41,7 +43,7 @@
 			b = b[m:]
 			parent.StripEnumPrefix = int(v)
 		default:
-			panic(fmt.Sprintf("unkown field number %d while unmarshalling GoFeatures", num))
+			panic(fmt.Sprintf("unknown field number %d while unmarshalling GoFeatures", num))
 		}
 	}
 	return parent
@@ -76,7 +78,7 @@
 				// DefaultSymbolVisibility is enforced in protoc, runtimes should not
 				// inspect this value.
 			default:
-				panic(fmt.Sprintf("unkown field number %d while unmarshalling FeatureSet", num))
+				panic(fmt.Sprintf("unknown field number %d while unmarshalling FeatureSet", num))
 			}
 		case protowire.BytesType:
 			v, m := protowire.ConsumeBytes(b)
@@ -150,7 +152,7 @@
 			_, m := protowire.ConsumeVarint(b)
 			b = b[m:]
 		default:
-			panic(fmt.Sprintf("unkown field number %d while unmarshalling EditionDefault", num))
+			panic(fmt.Sprintf("unknown field number %d while unmarshalling EditionDefault", num))
 		}
 	}
 }