Suppress logging outputs to honor -q option

After introducing log.[ch] in 2e87a75, the behavior of -q option is not
honored. This fix it.

Close #561

Author: ChinYikMing

src/main.c

@@ -273,6 +273,12 @@ int main(int argc, char **args)
     attr.data.user.elf_program = opt_prog_name;
 #endif
 
+    /* enable or disable the logging outputs */
+    if (opt_quiet_outputs)
+        rv_log_set_quiet(true);
+    else
+        rv_log_set_quiet(false);
+
     /* create the RISC-V runtime */
     rv = rv_create(&attr);
     if (!rv) {

src/riscv.c

@@ -417,9 +417,6 @@ riscv_t *rv_create(riscv_user_t rv_attr)
     rv_log_set_level(attr->log_level);
     rv_log_info("Log level: %s", rv_log_level_string(attr->log_level));
 
-    /* enable the log */
-    rv_log_set_quiet(false);
-
 #if !RV32_HAS(SYSTEM) || (RV32_HAS(SYSTEM) && RV32_HAS(ELF_LOADER))
     elf_t *elf = elf_new();
     assert(elf);