Changed the lvm-nm alias "-s" for -print-armap to "-M".

Changed the lvm-nm alias "-s" for -print-armap to "-M".
This will allow the "-s" flag to implemented in the future as it
is in darwin’s nm(1) to list symbols only in the specified section.

Given a LGTM by Shankar Easwaran who originally implemented
the support for lvm-nm’s -print-armap and archive map symbols.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212576 91177308-0d34-0410-b5e6-96231b3b80d8