[ARM] - Tidy-up ARMAsmPrinter.cpp

Change to range-loop where missing.

Reviwewed by: @fhahn, @asb
Differential Revision: https://reviews.llvm.org/D37199



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311993 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed