[Scalar] Use std::none_of (NFC) (#143282)

While I am at it, this patch replaces It with std::next(It) for clarity.

Note that It is not used after this point.

Author: kazutakahirata

llvm/lib/Transforms/Scalar/LICM.cpp

@@ -786,8 +786,8 @@ class ControlFlowHoister {
       return InitialPreheader;
     }
     BranchInst *BI = It->first;
-    assert(std::find_if(++It, HoistableBranches.end(), HasBBAsSuccessor) ==
-               HoistableBranches.end() &&
+    assert(std::none_of(std::next(It), HoistableBranches.end(),
+                        HasBBAsSuccessor) &&
            "BB is expected to be the target of at most one branch");
 
     LLVMContext &C = BB->getContext();