media: [next] media: vidtv: fix a read from an object after it has been freed

Currently the call to vidtv_psi_pat_table_destroy frees the object
m->si.pat however m->si.pat->num_pmt is being accessed after the
free.  Fix this by destroying m->si.pat after the m->si.pmt_secs[]
objects have been freed.

Addresses-Coverity: ("Read from pointer after free")

Reported-by: Cengiz Can <cengiz@kernel.wtf> # sent a similar fix about the same time

Fixes: 039b7cae ("media: vidtv: add a PID entry for the NIT table")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>