[Linux] Process.memory_maps() should remove `(deleted)` from "path"

[giampaolo]

======================================================================
FAIL: test_memory_maps (test_process.TestProcess)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_process.py", line 601, in test_memory_maps
    os.path.islink(nt.path), nt.path
AssertionError: /run/shm/sem.SiOnY9 (deleted)

[giampaolo]

Fixed in cc16e96.