Update test counter_promo_nest.c to meet llvm change

The test expects to see the pattern "load add store" twice
in a row.

However the test contains actually several instances of this pattern.
Currently the first pattern appears in the output twice.

But after LLVM change https://reviews.llvm.org/D42691 some addtional
modification is done and one of another pattern has been hoisted in
function entry block.

As a result we have another order of meeting this pattern.
The test is updated to meet this change.

llvm-svn: 324571