[MustExec] Drop duplicate RUN line (NFC)

Author: nikic

llvm/test/Analysis/MustExecute/const-cond.ll

@@ -1,6 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -disable-output -passes=print-mustexecute %s 2>&1 | FileCheck %s
-; RUN: opt -disable-output -passes=print-mustexecute %s 2>&1 | FileCheck %s
 
 ; In general the CFG below is easily simplified but this is useful for
 ; pass ordering issue elimination.