Merge pull request #2320 from xiagao/bz1858663-mem-backend

virtio-fs: update memory backend config

qemu/tests/cfg/virtio_fs_multi_vms.cfg

@@ -9,7 +9,7 @@
     start_vm = yes
     mem = 4096
     mem_devs = mem1
-    backend_mem1 = memory-backend-file
+    backend_mem_mem1 = memory-backend-file
     size_mem1 = 4G
     use_mem_mem1 = no
     share_mem = yes

qemu/tests/cfg/virtio_fs_readonly.cfg

@@ -18,7 +18,7 @@
     fs_dest = '/mnt/${fs_target}'
     mem = 4096
     mem_devs = mem1
-    backend_mem1 = memory-backend-file
+    backend_mem_mem1 = memory-backend-file
     mem-path_mem1 = /dev/shm
     size_mem1 = 4G
     use_mem_mem1 = no

qemu/tests/cfg/virtio_fs_share_data.cfg

@@ -18,7 +18,7 @@
     fs_driver_props = {"queue-size": 1024}
     mem = 4096
     mem_devs = mem1
-    backend_mem1 = memory-backend-file
+    backend_mem_mem1 = memory-backend-file
     mem-path_mem1 = /dev/shm
     size_mem1 = 4G
     use_mem_mem1 = no