Explanation on Uninitialized Variable bio in blk_rq_prep_clone

[SurajSonawane2415]

Explaination of how bio could be used uninitialized in this function:

In the function blk_rq_prep_clone, the variable bio is declared but can remain uninitialized 
if the allocation with bio_alloc_clone fails. This can lead to undefined behavior when the 
function attempts to free bio in the error handling section using bio_put(bio). 
By initializing bio to NULL at declaration, we ensure that the cleanup code will only 
interact with bio if it has been successfully allocated.

Best regards,
Suraj Sonawane