Drop unnecessary friend declarations

src/patchelf.h

@@ -67,8 +67,6 @@ private:
         }
     };
 
-    friend struct CompPhdr;
-
     void sortPhdrs();
 
     struct CompShdr
@@ -80,8 +78,6 @@ private:
         }
     };
 
-    friend struct CompShdr;
-
     [[nodiscard]] unsigned int getPageSize() const noexcept;
 
     void sortShdrs();