6831225: Upgrade JPRT jobs to use newer Linux 2.6 (e.g. Fedora 9)

Reviewed-by: tbell
diff --git a/jdk/make/jprt.properties b/jdk/make/jprt.properties
index a1e7e51..5e21dba 100644
--- a/jdk/make/jprt.properties
+++ b/jdk/make/jprt.properties
@@ -32,8 +32,8 @@
 solaris_sparcv9_5.10,\
 solaris_i586_5.10,\
 solaris_x64_5.10,\
-linux_i586,\
-linux_x64,\
+linux_i586_2.6,\
+linux_x64_2.6,\
 windows_i586,\
 windows_x64