Lock mutex in the same order.

SBProcess uses 2 mutexex; RunLock and APILock. Apart from 2 places, RunLock
is locked before API lock. I have fixed the 2 places where order was different.
I observed a deadlock due to this different order in lldb-mi once. Although
lldb-mi command and event thread dont run at the same time now. So it can not deadlock
there but can still be problem for some other clients.

Pre-approved by Greg in http://lists.cs.uiuc.edu/pipermail/lldb-dev/2015-February/006509.html

llvm-svn: 228844