src/CMakeLists.txt: supress more warnings

 - We already have -Wall
   So thes options without no- are redundant.
   and overloaded-virtual generates one warning for every line
   when compiling with Clang.

Signed-off-by: Willem Jan Withagen <wjw@digiware.nl>

src/CMakeLists.txt

@@ -113,7 +113,7 @@ else(no_yasm)
 endif(no_yasm)
 
 set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -ftemplate-depth-1024 -Wno-invalid-offsetof")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wnon-virtual-dtor -Woverloaded-virtual")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wnon-virtual-dtor -Wno-overloaded-virtual")
 if(CMAKE_CXX_COMPILER_ID STREQUAL GNU)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wstrict-null-sentinel")
 endif(CMAKE_CXX_COMPILER_ID STREQUAL GNU)