s390x/flic: cache flic in s390_get_flic

s390_get_flic() is called many times to obtain the flic. This wastes a
lot of time as it calls object_resolve_path() every time. Let's cache
S390FLICState by defining it as static.
Signed-off-by: NFei Li <sherrylf@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>

hw/intc/s390_flic.c

@@ -21,11 +21,14 @@
 
 S390FLICState *s390_get_flic(void)
 {
-    S390FLICState *fs;
+    static S390FLICState *fs;
 
-    fs = S390_FLIC_COMMON(object_resolve_path(TYPE_KVM_S390_FLIC, NULL));
     if (!fs) {
-        fs = S390_FLIC_COMMON(object_resolve_path(TYPE_QEMU_S390_FLIC, NULL));
+        fs = S390_FLIC_COMMON(object_resolve_path(TYPE_KVM_S390_FLIC, NULL));
+        if (!fs) {
+            fs = S390_FLIC_COMMON(object_resolve_path(TYPE_QEMU_S390_FLIC,
+                                                      NULL));
+        }
     }
     return fs;
 }