testsuite.at: pwd for windows.

testsuite.at: pwd for windows.

On MinGW, "pwd -W" gives the present working directory
in the form of windows path (i.e C:/temp instead of /c/temp).
When we pass the directory path to daemons as arguments,
we should be passing it in the form of windows path.

Suggested-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>