Switch tests over to use the 'not' script, instead of explicit control flow

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6959 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/LevelRaise/2002-05-02-MissedRaise.ll

@@ -1,9 +1,6 @@
 ; This testcase is not level raised properly...
 ;
-; RUN: if as < %s | opt -raise | dis | grep ' cast ' | grep '*'
-; RUN: then exit 1
-; RUN: else exit 0
-; RUN: fi
+; RUN: as < %s | opt -raise | dis | grep ' cast ' | not grep '*'
 
 	%List = type { int, %List* }