TWRP MTP: make sure inotify_fd is set

Originally the inotify_init() call was part of a separate thread
which would occasionally allow the readDirs function to run and
start trying to add watches before inotify_fd was init'ed properly
and result in the add watch failing. This patch set relocates the
inotify_init call to happen outside and before starting the
separate thread to ensure that inotify_fd is set properly.

Change-Id: I8748c23473b60b57887df9d692834f3d2b249802