cmd/syncthing, lib/fs, lib/sync: Spelling in comments

lib/fs/mtimefs_test.go

@@ -45,7 +45,7 @@ func TestMtimeFS(t *testing.T) {
 		t.Error("Should not have failed:", err)
 	}
 
-	// All of the calls were successfull, so an Lstat on them should return
+	// All of the calls were successful, so an Lstat on them should return
 	// the test timestamp.
 
 	for _, file := range []string{"testdata/exists0", "testdata/exists1", "testdata/exists2"} {

lib/sync/sync_test.go

@@ -234,7 +234,7 @@ func TestTimeoutCond(t *testing.T) {
 	// See the comments in runLocks
 
 	const (
-		// Low values to avoid being intrusive in continous testing. Can be
+		// Low values to avoid being intrusive in continuous testing. Can be
 		// increased significantly for stress testing.
 		iterations = 100
 		routines   = 10