[Issue]: videodecode Sample has code that will never be executed

[essamROCm]

In the "videodecode.cpp Sample":

Variable "use_threading" not used, declared in line 163, and supposed to be used in the following 'if' block.

Line 268, the second part of the 'if' block, will never be executed due to mistakenly using variable 'backend' in line 265 as a condition, which is at that line will always be '1' or true.