Fix FPDF_GetPageLabel API typo.

public/fpdf_doc.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 PUBLIC_FPDF_DOC_H_
 #define PUBLIC_FPDF_DOC_H_
 
 // NOLINTNEXTLINE(build/include)
@@ skipping 295 matching lines @@
 //   document    - handle to the document.
 //   page_index  - the 0-based index of the page.
 //   buffer      - a buffer for the page label. May be NULL.
 //   buflen      - the length of the buffer, in bytes. May be 0.
 //
 // Returns the number of bytes in the page label, including trailing zeros.
 //
 // The |buffer| is always encoded in UTF-16LE. The |buffer| is followed by two
 // bytes of zeros indicating the end of the string.  If |buflen| is less than
 // the returned length, or |buffer| is NULL, |buffer| will not be modified.
-DLLEXPORT unsigned long STDCALL FPDF_GetPagelLabel(FPDF_DOCUMENT document,
-                                                   int page_index,
-                                                   void* buffer,
-                                                   unsigned long buflen);
+DLLEXPORT unsigned long STDCALL FPDF_GetPageLabel(FPDF_DOCUMENT document,
+                                                  int page_index,
+                                                  void* buffer,
+                                                  unsigned long buflen);
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif  // __cplusplus
 
 #endif  // PUBLIC_FPDF_DOC_H_