fix last 4 warnings

Author: mloit

Sources/web3swift/Convenience/Data+Extension.swift

@@ -9,8 +9,9 @@ import Foundation
 public extension Data {
 
     init<T>(fromArray values: [T]) {
-        var values = values
-        self.init(buffer: UnsafeBufferPointer(start: &values, count: values.count))
+        let values = values
+        let ptrUB = values.withUnsafeBufferPointer { (ptr: UnsafeBufferPointer) in return ptr }
+        self.init(buffer: ptrUB)
     }
 
     func toArray<T>(type: T.Type) throws -> [T] {

Sources/web3swift/Convenience/SECP256k1.swift

@@ -116,7 +116,7 @@ extension SECP256K1 {
         let result = privateKey.withUnsafeBytes { (pkRawBufferPointer: UnsafeRawBufferPointer) -> Int32? in
             if let pkRawPointer = pkRawBufferPointer.baseAddress, pkRawBufferPointer.count > 0 {
                 let privateKeyPointer = pkRawPointer.assumingMemoryBound(to: UInt8.self)
-                let res = secp256k1_ec_pubkey_create(context!, UnsafeMutablePointer<secp256k1_pubkey>(&publicKey), privateKeyPointer)
+                let res = secp256k1_ec_pubkey_create(context!, &publicKey, privateKeyPointer)
                 return res
             } else {
                 return nil
@@ -163,7 +163,7 @@ extension SECP256K1 {
         let result = serializedKey.withUnsafeBytes { (serializedKeyRawBufferPointer: UnsafeRawBufferPointer) -> Int32? in
             if let serializedKeyRawPointer = serializedKeyRawBufferPointer.baseAddress, serializedKeyRawBufferPointer.count > 0 {
                 let serializedKeyPointer = serializedKeyRawPointer.assumingMemoryBound(to: UInt8.self)
-                let res = secp256k1_ec_pubkey_parse(context!, UnsafeMutablePointer<secp256k1_pubkey>(&publicKey), serializedKeyPointer, keyLen)
+                let res = secp256k1_ec_pubkey_parse(context!, &publicKey, serializedKeyPointer, keyLen)
                 return res
             } else {
                 return nil

Sources/web3swift/KeystoreManager/BIP32HDNode.swift

@@ -79,10 +79,7 @@ public class HDNode {
         }
         depth = data[4..<5].bytes[0]
         parentFingerprint = data[5..<9]
-        let cNum = data[9..<13].bytes
-        childNumber = UnsafePointer(cNum).withMemoryRebound(to: UInt32.self, capacity: 1) {
-            $0.pointee
-        }
+        childNumber = data[9..<13].bytes.withUnsafeBytes { $0.load(as: UInt32.self) }
         chaincode = data[13..<45]
         if serializePrivate {
             privateKey = data[46..<78]