The analyzer detected a function that receives a call to itself as an argument.
Consider the following example:
char lower_ch = tolower(tolower(ch));
The second function call is redundant. Perhaps this sample contains a typo and the programmer actually meant to call to some other function instead. If there is no mistake, then the extra call should be removed because expressions like that look suspicious:
char lower_ch = tolower(ch);
if (islower(islower(ch))) do_something();
The 'islower' function returns a value of type 'int' and can be used as an argument to itself. This expression contains an error and serves no purpose.