ENGCOM-1614: [Backport] Fixed typo mistake in function comment #15396

 - Merge Pull Request #15396 from dmytro-ch/magento2:2.1-develop-PR-port-15302
 - Merged commits:
   1. 2c31e4d
   2. 32c4a33
   3. c13e1fd
   4. 07e3a8f

Author: magento-engcom-team

app/code/Magento/Paypal/Model/Api/Nvp.php

@@ -1027,7 +1027,7 @@ public function callGetPalDetails()
     }
 
     /**
-     * Set Customer BillingA greement call
+     * Set Customer BillingAgreement call
      *
      * @return void
      * @link https://cms.paypal.com/us/cgi-bin/?&cmd=_render-content&content_ID=developer/e_howto_api_nvp_r_SetCustomerBillingAgreement
@@ -1418,15 +1418,15 @@ protected function _deformatNVP($nvpstr)
         $nvpstr = strpos($nvpstr, "\r\n\r\n") !== false ? substr($nvpstr, strpos($nvpstr, "\r\n\r\n") + 4) : $nvpstr;
 
         while (strlen($nvpstr)) {
-            //postion of Key
+            //position of Key
             $keypos = strpos($nvpstr, '=');
             //position of value
             $valuepos = strpos($nvpstr, '&') ? strpos($nvpstr, '&') : strlen($nvpstr);
 
             /*getting the Key and Value values and storing in a Associative Array*/
             $keyval = substr($nvpstr, $intial, $keypos);
             $valval = substr($nvpstr, $keypos + 1, $valuepos - $keypos - 1);
-            //decoding the respose
+            //decoding the response
             $nvpArray[urldecode($keyval)] = urldecode($valval);
             $nvpstr = substr($nvpstr, $valuepos + 1, strlen($nvpstr));
         }