schema: require target path in storage pool xml

Make target path mandatory for pool types that require target,
since we refuse to parse a target without a path.

https://bugzilla.redhat.com/show_bug.cgi?id=893273

docs/schemas/storagepool.rng

@@ -200,11 +200,9 @@
 
   <define name='target'>
     <element name='target'>
-      <optional>
       <element name='path'>
         <ref name='absFilePath'/>
       </element>
-      </optional>
       <ref name='permissions'/>
     </element>
   </define>

tests/Makefile.am

@@ -73,6 +73,7 @@ EXTRA_DIST =		\
 	securityselinuxlabeldata \
 	schematestutils.sh \
 	sexpr2xmldata \
+	storagepoolschemadata \
 	storagepoolschematest \
 	storagepoolxml2xmlin \
 	storagepoolxml2xmlout \

tests/storagepoolschemadata/dir-missing-target-path-invalid.xml

@@ -0,0 +1,12 @@
+<pool type='dir'>
+  <name>test</name>
+  <source>
+  </source>
+  <target>
+    <permissions>
+      <mode>0700</mode>
+      <owner>-1</owner>
+      <group>-1</group>
+    </permissions>
+  </target>
+</pool>

tests/storagepoolschematest

@@ -4,7 +4,7 @@
 . $srcdir/test-lib.sh
 . $abs_srcdir/schematestutils.sh
 
-DIRS="storagepoolxml2xmlin storagepoolxml2xmlout"
+DIRS="storagepoolxml2xmlin storagepoolxml2xmlout storagepoolschemadata"
 SCHEMA="storagepool.rng"
 
 check_schema "$DIRS" "$SCHEMA"