change default $mysql_tree

scripts/common.sh

@@ -157,15 +157,12 @@ function parse_mysqlbuild() {
         else
             git_tag=HEAD
             # setup _tree defaults
-            if [ -z $mysql_tree ] ; then mysql_tree=$mysql_version; fi
+            if [ -z $mysql_tree ] ; then mysql_tree=$mysql_distro-$mysql_version; fi
             if [ -z $jemalloc_tree ] ; then jemalloc_tree=$jemalloc_version; fi
         fi
-        # 5.6 is in another repo
         mysql_repo=$mysql_distro
-        if [[ $mysql_distro = mysql && $mysql_version =~ ^5.6 ]] ; then 
-            mysql_repo=mysql56
-            mysql_tree=$mysql_distro-$mysql_version
-        fi
+        # 5.6 is in another repo
+        if [[ $mysql_distro = mysql && $mysql_version =~ ^5.6 ]] ; then mysql_repo=mysql56; fi
     else
         exitcode=1
     fi