Commit 25e5e4c7 broke compilation for non POSIX hosts (e.g. MinGW)
because it partially replaced "ret" by "count".

It also changed the handling of EINTR in a wrong way.

The patch restores the old code for these two changes.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>