Bug fix from Eric Norum:

After weeks of trying to figure why my RTEMS/KASQ server crashes now
    and then I found a nasty bug I introduced in adding multiple-driver
    support to libio.  The bug only affects `add-on' driver classes (like
    the networking code).  Old-style file descriptors were not affected.

    The bug cleared 32 bytes of memory (unspecified location) whenever a
    `close' of a socket was performed!  I was clearing an IOP I hadn't
    allocated -- and the pointer wasn't initiallized, either!

c/src/exec/libcsupport/src/libio.c

@@ -338,7 +338,6 @@ __rtems_close(
             return -1;
         }
         status = (*fp)(fd);
-        rtems_libio_free(iop);
         return status;
     }
     iop = rtems_libio_iop(fd);

c/src/lib/libc/libio.c

@@ -338,7 +338,6 @@ __rtems_close(
             return -1;
         }
         status = (*fp)(fd);
-        rtems_libio_free(iop);
         return status;
     }
     iop = rtems_libio_iop(fd);

cpukit/libcsupport/src/libio.c

@@ -338,7 +338,6 @@ __rtems_close(
             return -1;
         }
         status = (*fp)(fd);
-        rtems_libio_free(iop);
         return status;
     }
     iop = rtems_libio_iop(fd);