Fix -Wformat error with explicit void* -> char* cast.

hardware/ril/reference-ril/reference-ril.c:1841:46: error: format specifies type 'char *' but the argument has type 'void *' [-Werror,-Wformat]
    snprintf(cmd, sizeof(cmd), "AT+CCHO=%s", data);
                                        ~~   ^~~~

Bug: http://b/155835175
Test: m
Change-Id: I7fd819c6c452b56aae15429344320c4cdaed702c
1 file changed