vita: Drop memcmp redirect to sceClibMemcmp.

CMakeLists.txt

@@ -2495,7 +2495,6 @@ elseif(VITA)
   target_compile_definitions(sdl-build-options INTERFACE "-Dmemcpy=sceClibMemcpy")
   target_compile_definitions(sdl-build-options INTERFACE "-Dmemset=sceClibMemset")
   target_compile_definitions(sdl-build-options INTERFACE "-Dmemmove=sceClibMemmove")
-  target_compile_definitions(sdl-build-options INTERFACE "-Dmemcmp=sceClibMemcmp")
 
 #  CheckPTHREAD()