tests: Add storagepool xml test for netfs-auto

Cover the case where @netauto would be used to create the command
line in virStorageBackendFileSystemMountCmd. Essentially when the
pool type is "netfs", but the "source.format" is empty, create the
command line properly.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
ACKed-by: NMichal Privoznik <mprivozn@redhat.com>

tests/storagepoolxml2argvdata/pool-netfs-auto.argv

+mount localhost:/var/lib/libvirt/images /mnt

tests/storagepoolxml2argvtest.c

@@ -146,6 +146,7 @@ mymain(void)
     DO_TEST_FAIL("pool-iscsi");
     DO_TEST_FAIL("pool-iscsi-auth");
     DO_TEST("pool-netfs");
+    DO_TEST("pool-netfs-auto");
     DO_TEST("pool-netfs-gluster");
     DO_TEST("pool-netfs-cifs");
     DO_TEST_FAIL("pool-scsi");

tests/storagepoolxml2xmlin/pool-netfs-auto.xml

+<pool type='netfs'>
+  <name>nfsimages</name>
+  <uuid>7641d5a8-af11-f730-a34e-0a7dfcede71f</uuid>
+  <capacity>0</capacity>
+  <allocation>0</allocation>
+  <available>0</available>
+  <source>
+    <host name='localhost'/>
+    <dir path='/var/lib/libvirt/images'/>
+  </source>
+  <target>
+    <path>/mnt</path>
+    <permissions>
+      <mode>0700</mode>
+      <owner>0</owner>
+      <group>0</group>
+    </permissions>
+  </target>
+</pool>

tests/storagepoolxml2xmlout/pool-netfs-auto.xml

+<pool type='netfs'>
+  <name>nfsimages</name>
+  <uuid>7641d5a8-af11-f730-a34e-0a7dfcede71f</uuid>
+  <capacity unit='bytes'>0</capacity>
+  <allocation unit='bytes'>0</allocation>
+  <available unit='bytes'>0</available>
+  <source>
+    <host name='localhost'/>
+    <dir path='/var/lib/libvirt/images'/>
+    <format type='auto'/>
+  </source>
+  <target>
+    <path>/mnt</path>
+    <permissions>
+      <mode>0700</mode>
+      <owner>0</owner>
+      <group>0</group>
+    </permissions>
+  </target>
+</pool>

tests/storagepoolxml2xmltest.c

@@ -82,6 +82,7 @@ mymain(void)
     DO_TEST("pool-iscsi");
     DO_TEST("pool-iscsi-auth");
     DO_TEST("pool-netfs");
+    DO_TEST("pool-netfs-auto");
     DO_TEST("pool-netfs-gluster");
     DO_TEST("pool-netfs-cifs");
     DO_TEST("pool-scsi");