Add missing TEMP_FAILURE_RETRYs in dt_fd_forward

There were several syscalls that should have had a TEMP_FAILURE_RETRY
but did not. This could cause the connection to be dropped
unexpectedly if there was a signal.

Test: build
Test: ./tools/dt_fds_forward.py  \
        ./test/run-test --host --dev 001-HelloWorld
Test: jdb -attach localhost:12345
Test: kill -3 <pid of dalvikvm>

Change-Id: I62a3409d3e2947db1c7142547c925d1d2ba9eecd