libdvbv5: Fix the speedup scan condition

The DVB table read routine has 3 operational modes: it can seek for an
specific table section, it can expect sequential table sections, or it
can wait non-sequencial sections, stopping when a section is duplicated.

The second mode (sequencial table sections) finishes the reading after
receiving all table sections from 0 to the max table section, speeding
up its reception, while being more reliant to section errors.

However, the tests for the stop condition for this mode were wrong.

Fix it.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>