staging: csr: wait for the exec in usermodehelper

The order of wait values has been changed by commit 9d944ef3.
Fix the wait parameter and start to use a define instead of
"magic number".

Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>