This code does not call deinit_card(card); in an error case, as done in
other error-handling code in the same function. But actually, the called
function init_sram can only return 0, so there is no need for the error
check at all.
init_sram is also given a void return type, and its single return statement
at the end of the function is dropped.
A simplified version of the sematic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)