fixed a few warnings (signed-unsigned comparisions, unused param)

elfio/elfio_dump.hpp

@@ -604,7 +604,7 @@ class dump
                             << "        Name"
                             << std::endl;
                     }
-                    for ( int i = 0; i < sym_no; ++i ) {
+                    for ( Elf_Xword i = 0; i < sym_no; ++i ) {
                         std::string   name;
                         Elf64_Addr    value;
                         Elf_Xword     size;
@@ -727,7 +727,7 @@ class dump
                 if ( dyn_no > 0 ) {
                     out << "Dynamic section (" << sec->get_name() << ")" << std::endl;
                     out << "[  Nr ] Tag              Name/Value" << std::endl;
-                    for ( int i = 0; i < dyn_no; ++i ) {
+                    for ( Elf_Xword i = 0; i < dyn_no; ++i ) {
                         Elf_Xword   tag;
                         Elf_Xword   value;
                         std::string str;
@@ -751,7 +751,7 @@ class dump
                  Elf_Xword     tag,
                  Elf_Xword     value,
                  std::string   str,
-                 unsigned int  elf_class )
+                 unsigned int  /*elf_class*/ )
     {
             out << "[" 
                 << DUMP_DEC_FORMAT(  5 ) << no