The analyzer detected a potential error: there is a variable in code which is defined and initialized but not being used further. Besides, there is a variable in the exterior scope which also has the same name and type. It is highly probable that the programmer intended to use an already existing variable instead of defining a new one.
Let's examine this sample:
BOOL ret = TRUE; if (m_hbitmap) BOOL ret = picture.SaveToFile(fptr);
The programmer defined a new variable 'ret' by accident, which causes the previous variable to always have the TRUE value regardless if the picture is saved into a file successfully or not. This is the correct code:
BOOL ret = TRUE; if (m_hbitmap) ret = picture.SaveToFile(fptr);
According to Common Weakness Enumeration, potential errors found by using this diagnostic are classified as CWE-563.
You can look at examples of errors detected by the V561 diagnostic.