Fix yara3 compilation about radare2-extras HOT 3 CLOSED

cc -I/tmp/r2/include/libr  -I/include -I. -fPIC   -c -o core_yara3.o core_yara3.c
core_yara3.c: In function ‘r_cmd_yara_scan’:
core_yara3.c:76:3: warning: passing argument 6 of ‘yr_rules_scan_mem’ makes integer from pointer without a cast [enabled by default]
   yr_rules_scan_mem (rules, to_scan, to_scan_size, 0, callback, NULL, 0);
   ^
In file included from core_yara3.c:6:0:
/usr/include/yara.h:703:5: note: expected ‘int’ but argument is of type ‘void *’
 int yr_rules_scan_mem(
     ^
core_yara3.c: In function ‘r_cmd_yara_show’:
core_yara3.c:91:34: error: expected ‘;’ before ‘{’ token
   yr_rules_foreach (rules, rule) {
                                  ^
core_yara3.c: In function ‘r_cmd_yara_tags’:
core_yara3.c:112:33: error: expected ‘;’ before ‘{’ token
   yr_rules_foreach(rules, rule) {
                                 ^
core_yara3.c: In function ‘r_cmd_yara_tag’:
core_yara3.c:140:34: error: expected ‘;’ before ‘{’ token
   yr_rules_foreach (rules, rule) {
                                  ^
core_yara3.c: In function ‘r_cmd_yara_list’:
core_yara3.c:160:34: error: expected ‘;’ before ‘{’ token
   yr_rules_foreach (rules, rule) {
                                  ^
core_yara3.c: In function ‘r_cmd_yara_add_file’:
core_yara3.c:276:2: error: too many arguments to function ‘yr_compiler_add_file’
  result = yr_compiler_add_file (compiler, rules_file, NULL, rules_path);
  ^
In file included from core_yara3.c:6:0:
/usr/include/yara.h:649:5: note: declared here
 int yr_compiler_add_file(
     ^
make: *** [core_yara3.o] Error 1