Hi,
This is another little patch to make the test messages unique in  
mi-var-block.exp. Tested by running the test. Is it ok?

Regards,
Abid

gdb/testsuite:

2013-01-21  Hafiz Abid Qadeer<abidh@codesourcery.com>

         PR gdb/13443
         * gdb.mi/mi-var-block.exp: Make test messages unique.