Correct typo in form fill environment functions

fpdfsdk/include/fpdf_dataavail.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef _FPDF_DATAAVAIL_H_
 #define _FPDF_DATAAVAIL_H_
 
 #ifndef _FPDFVIEW_H_
@@ skipping 173 matching lines @@
 * Return value:
 *                       Non-zero for Form data is fully available, 0 for Form data not yet available.
 *                       Details: -1 - error, the input parameter not correct, such as hints is null.
 *                                        0  - data not available
 *                                        1  - data available
 *                                        2  - no form data.                             
 * Comments:
 *                       This function call be called only after FPDFAvail_GetDocument if called. 
 *                       The application should call this function whenever new data arrived, and process all the
 *                       generated download hints if any, until the function returns non-zero value. Then the 
-*                       application can perform page loading. Recommend to call FPDFDOC_InitFormFillEnviroument
+*                       application can perform page loading. Recommend to call FPDFDOC_InitFormFillEnvironment
 *                       after the function returns non-zero value.
 */
 DLLEXPORT int STDCALL FPDFAvail_IsFormAvail(FPDF_AVAIL avail, FX_DOWNLOADHINTS* hints);
 
 /**
 * Function: FPDFAvail_IsLinearized
 *                       To check whether a document is Linearized PDF file.
 *
 * Parameters:
 *                       avail           -       Handle to document availability provider returned by FPDFAvail_Create
 * Return value:
 *                       return TRUE means the document is linearized PDF else not.
 *                       FSDK_IS_LINEARIZED is a linearize file.
 *                       FSDK_NOT_LINEARIZED is not a linearize file.
 *                       FSDK_UNKNOW_LINEARIZED don't know whether the file is a linearize file.
 * Comments:
 *                       It return TRUE/FALSE as soon as we have first 1K data.  If the file's size less than
 *                       1K,we don't known whether the PDF is a linearized file.
 *
 */
 DLLEXPORT FPDF_BOOL STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail);
 
 #ifdef __cplusplus
 };
 #endif
 
 #endif