Change zstdcli's main() declaration due to -Wmain on some compilers

programs/zstdcli.c

@@ -741,7 +741,7 @@ typedef enum { zom_compress, zom_decompress, zom_test, zom_bench, zom_train, zom
 # define MAXCLEVEL  ZSTD_maxCLevel()
 #endif
 
-int main(int CONST_ARGC argCount, const char* argv[])
+int main(int argCount, const char* argv[])
 {
     int argNb,
         followLinks = 0,