i#1551 port to ARM: fix bug in mangle_gpr_list_write()
i#1551 port to ARM: fix bug in mangle_gpr_list_write()

Fix bug in mangle_gpr_list_write() from
bd563ab2bb7d6a870bde19f40fb7d797cdac63e3 where the code fails to write the
updated stolen reg value back.

Review-URL: https://codereview.appspot.com/201540043

AmesianX/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,sigma-random/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,code4bones/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,bl4ckic3/dynamorio,sigma-random/dynamorio,AmesianX/dynamorio,sigma-random/dynamorio,code4bones/dynamorio,sigma-random/dynamorio,daksunt/dynamorio,daksunt/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,daksunt/dynamorio,code4bones/dynamorio