Fix 'expression too complex'

Sources/CryptoSwift/AES.swift

@@ -206,12 +206,13 @@ fileprivate extension AES {
         b2 = F1(t[2], t[3], t[0], t[1]) ^ rk[rounds][2]
         b3 = F1(t[3], t[0], t[1], t[2]) ^ rk[rounds][3]
 
-        return [
+        let encrypted: Array<UInt8> = [
             UInt8(b0 & 0xFF),UInt8((b0 >> 8) & 0xFF),UInt8((b0 >> 16) & 0xFF),UInt8((b0 >> 24) & 0xFF),
             UInt8(b1 & 0xFF),UInt8((b1 >> 8) & 0xFF),UInt8((b1 >> 16) & 0xFF),UInt8((b1 >> 24) & 0xFF),
             UInt8(b2 & 0xFF),UInt8((b2 >> 8) & 0xFF),UInt8((b2 >> 16) & 0xFF),UInt8((b2 >> 24) & 0xFF),
             UInt8(b3 & 0xFF),UInt8((b3 >> 8) & 0xFF),UInt8((b3 >> 16) & 0xFF),UInt8((b3 >> 24) & 0xFF)
-        ] as Array<UInt8>
+        ]
+        return encrypted
     }
 
     func decrypt(block: Array<UInt8>) -> Array<UInt8>? {