vnc: Simplify vnc_display_password()

Drop the qerror_report() call from it and let its callers set the error
themselves. This also allows for dropping the 'ret' variable.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

console.h

@@ -384,7 +384,6 @@ int vnc_display_pw_expire(DisplayState *ds, time_t expires);
 #else
 static inline int vnc_display_password(DisplayState *ds, const char *password)
 {
-    qerror_report(QERR_FEATURE_DISABLED, "vnc");
     return -ENODEV;
 }
 static inline int vnc_display_pw_expire(DisplayState *ds, time_t expires)

monitor.c

@@ -929,7 +929,12 @@ static int set_password(Monitor *mon, const QDict *qdict, QObject **ret_data)
         }
         /* Note that setting an empty password will not disable login through
          * this interface. */
-        return vnc_display_password(NULL, password);
+        rc = vnc_display_password(NULL, password);
+        if (rc < 0) {
+            qerror_report(QERR_SET_PASSWD_FAILED);
+            return -1;
+        }
+        return 0;
     }
 
     qerror_report(QERR_INVALID_PARAMETER, "protocol");

ui/vnc.c

@@ -2686,19 +2686,16 @@ int vnc_display_disable_login(DisplayState *ds)
 
 int vnc_display_password(DisplayState *ds, const char *password)
 {
-    int ret = 0;
     VncDisplay *vs = ds ? (VncDisplay *)ds->opaque : vnc_display;
 
     if (!vs) {
-        ret = -EINVAL;
-        goto out;
+        return -EINVAL;
     }
 
     if (!password) {
         /* This is not the intention of this interface but err on the side
            of being safe */
-        ret = vnc_display_disable_login(ds);
-        goto out;
+        return vnc_display_disable_login(ds);
     }
 
     if (vs->password) {
@@ -2707,11 +2704,8 @@ int vnc_display_password(DisplayState *ds, const char *password)
     }
     vs->password = g_strdup(password);
     vs->auth = VNC_AUTH_VNC;
-out:
-    if (ret != 0) {
-        qerror_report(QERR_SET_PASSWD_FAILED);
-    }
-    return ret;
+
+    return 0;
 }
 
 int vnc_display_pw_expire(DisplayState *ds, time_t expires)