Remove unneeded byte overflow checks.

In addition, my compiler complains about some non-sensical byte
overflow checks, which break my build (with -Werror enabled):
Signed-off-by: Jean-Paul Saman <jpsaman@videolan.org>

src/descriptors/dr_40.c

@@ -61,8 +61,7 @@ dvbpsi_network_name_dr_t* dvbpsi_DecodeNetworkNameDr(
         return NULL;
 
     /* Decode data */
-    p_decoded->i_name_length = p_descriptor->i_length <= 255 ?
-                               p_descriptor->i_length : 255;
+    p_decoded->i_name_length = p_descriptor->i_length;
     if (p_decoded->i_name_length)
         memcpy(p_decoded->i_name_byte,
                p_descriptor->p_data,

src/descriptors/dr_73.c

@@ -58,9 +58,6 @@ dvbpsi_default_authority_dr_t *dvbpsi_DecodeDefaultAuthorityDr(dvbpsi_descriptor
     if (!p_decoded)
         return NULL;
 
-    if (p_descriptor->i_length > 255)
-        p_descriptor->i_length = 255;
-
     memcpy(&p_decoded->authority, p_descriptor->p_data, p_descriptor->i_length);
     p_decoded->authority[p_descriptor->i_length] = 0;
 

src/dvbpsi.c

@@ -216,7 +216,6 @@ void dvbpsi_decoder_reset(dvbpsi_decoder_t* p_decoder, const bool b_force)
 bool dvbpsi_decoder_psi_sections_completed(dvbpsi_decoder_t* p_decoder)
 {
     assert(p_decoder);
-    assert(p_decoder->i_last_section_number <= 255);
 
     bool b_complete = false;