[*] pickle: fix typos in comments

Author: dmitryikh

internal/pickle/numpy.go

@@ -71,7 +71,7 @@ func (a *NumpyArrayRaw) Build(build Build) (err error) {
 
 	switch x := args[4].(type) {
 	case Build, Reduce:
-		// if we've got Build or Reduce objects we have a deal with plaint data stored in raw byte array
+		// if we've got Build or Reduce objects we have a deal with plain data stored in raw byte array
 		err = ParseClass(&a.Data, args[4])
 	case List:
 		// sometimes we've got data stored as python list (for array of python objects)

internal/pickle/types.go

@@ -30,7 +30,7 @@ type Reduce struct {
 	Args     Tuple
 }
 
-// Build is result of BUILD pickle command (usualli class __setstate__ call)
+// Build is result of BUILD pickle command (usually class __setstate__ call)
 type Build struct {
 	Object interface{}
 	// Args are usually represented like Tuple (arguments for custom __setstate__) or Dict (class members)