qemuBuildMemoryBackendStr: Don't overwrite @force

This is an input argument. We should not overwrite it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_command.c

@@ -3302,7 +3302,6 @@ qemuBuildMemoryBackendStr(unsigned long long size,
 
         if (def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {
             /* we can have both pagesize and mem source, then check mem source first */
-            force = true;
             if (virJSONValueObjectAdd(props,
                                       "s:mem-path", cfg->memoryBackingDir,
                                       NULL) < 0)
@@ -3372,7 +3371,8 @@ qemuBuildMemoryBackendStr(unsigned long long size,
     }
 
     /* If none of the following is requested... */
-    if (!needHugepage && !userNodeset && !memAccess && !nodeSpecified && !force) {
+    if (!needHugepage && !userNodeset && !memAccess && !nodeSpecified &&
+        def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force) {
         /* report back that using the new backend is not necessary
          * to achieve the desired configuration */
         ret = 1;