nwfilter: use time_t for timeout for consistency

nwfilter: use time_t for timeout for consistency

Coverity scan reports:
"A time_t value is stored in an integer with too few bits to accommodate
it. The expression timeout is cast to unsigned int"

We are already casting and storing time_t timeout variable into unsigned int.
We can use time_t for timeout and cast it to unsigned long (should be big enough)
instead of unsigned int in sscanf, g_strdup_printf as required.

Signed-off-by: Shaleen Bathla <shaleen.bathla@oracle.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>