sdl: Fix memory leakage

Valgrind was so kind to remark that no one bothers to release keycodes
after use and that something is fishy about cleaning up the requested
keyboard descriptor. With this patch applied, we no longer leak about
12k during startup.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

sdl.c

@@ -268,32 +268,35 @@ static uint8_t sdl_keyevent_to_keycode(const SDL_KeyboardEvent *ev)
 static int check_for_evdev(void)
 {
     SDL_SysWMinfo info;
-    XkbDescPtr desc;
+    XkbDescPtr desc = NULL;
     int has_evdev = 0;
-    const char *keycodes;
+    char *keycodes = NULL;
 
     SDL_VERSION(&info.version);
-    if (!SDL_GetWMInfo(&info))
+    if (!SDL_GetWMInfo(&info)) {
         return 0;
-
+    }
     desc = XkbGetKeyboard(info.info.x11.display,
                           XkbGBN_AllComponentsMask,
                           XkbUseCoreKbd);
-    if (desc == NULL || desc->names == NULL)
-        return 0;
-
-    keycodes = XGetAtomName(info.info.x11.display, desc->names->keycodes);
-    if (keycodes == NULL)
-        fprintf(stderr, "could not lookup keycode name\n");
-    else if (strstart(keycodes, "evdev", NULL))
-        has_evdev = 1;
-    else if (!strstart(keycodes, "xfree86", NULL))
-        fprintf(stderr,
-                "unknown keycodes `%s', please report to qemu-devel@nongnu.org\n",
-                keycodes);
-
-    XkbFreeClientMap(desc, XkbGBN_AllComponentsMask, True);
+    if (desc && desc->names) {
+        keycodes = XGetAtomName(info.info.x11.display, desc->names->keycodes);
+        if (keycodes == NULL) {
+            fprintf(stderr, "could not lookup keycode name\n");
+        } else if (strstart(keycodes, "evdev", NULL)) {
+            has_evdev = 1;
+        } else if (!strstart(keycodes, "xfree86", NULL)) {
+            fprintf(stderr, "unknown keycodes `%s', please report to "
+                    "qemu-devel@nongnu.org\n", keycodes);
+        }
+    }
 
+    if (desc) {
+        XkbFreeKeyboard(desc, XkbGBN_AllComponentsMask, True);
+    }
+    if (keycodes) {
+        XFree(keycodes);
+    }
     return has_evdev;
 }
 #else