Make configure found g++ correctly

Author: SendaoYan

configure

@@ -1137,10 +1137,10 @@ preset_cxx="$CXX"
 if test -z "$CXX"
 then
         case "$ac_cv_cc_name" in
-        gcc)    AC_PATH_TOOL([CXX], [g++], [g++], [notfound]) ;;
-        cc)     AC_PATH_TOOL([CXX], [c++], [c++], [notfound]) ;;
-        clang)             AC_PATH_TOOL([CXX], [clang++], [clang++], [notfound]) ;;
-        icc)               AC_PATH_TOOL([CXX], [icpc], [icpc], [notfound]) ;;
+        gcc)    AC_PATH_TOOL([CXX], [g++], [notfound]) ;;
+        cc)     AC_PATH_TOOL([CXX], [c++], [notfound]) ;;
+        clang)             AC_PATH_TOOL([CXX], [clang++], [notfound]) ;;
+        icc)               AC_PATH_TOOL([CXX], [icpc], [notfound]) ;;
         esac
 	if test "$CXX" = "notfound"
 	then