Fix function declaration

V762 It is possible a virtual function was overridden incorrectly. See third argument of function 'printStructure' in derived class 'TiffImage' and base class 'Image'. tiffimage.hpp 93

include/exiv2/tiffimage.hpp

@@ -89,7 +89,7 @@ namespace Exiv2 {
                 not valid (does not look like data of the specific image type).
           @warning This function is not thread safe and intended for exiv2 -p{S|R} as a file debugging aid
          */
-        virtual void printStructure(std::ostream& out, PrintStructureOption option,int depth=-1);
+        virtual void printStructure(std::ostream& out, PrintStructureOption option,int depth=0);
 
         /*!
           @brief Not supported. TIFF format does not contain a comment.

src/tiffimage.cpp

@@ -184,7 +184,7 @@ namespace Exiv2 {
         // recursively print the structure to /dev/null to ensure all metadata is in memory
         // must be recursive to handle NEFs which stores the raw image in a subIFDs
         std::ofstream devnull;
-        printStructure(devnull,kpsRecursive,0);
+        printStructure(devnull,kpsRecursive);
         ByteOrder bo = TiffParser::decode(exifData_,
                                           iptcData_,
                                           xmpData_,