inspector: show the per-OS osinfo guess (RHBZ#1544842)

Output also the osinfo guess for each OS in the generated XML output;
adapt the RNG schema, and the test data to it.

inspector/expected-coreos.img.xml

@@ -8,6 +8,7 @@
     <major_version>899</major_version>
     <minor_version>13</minor_version>
     <hostname>coreos.invalid</hostname>
+    <osinfo>coreos899.13</osinfo>
     <mountpoints>
       <mountpoint dev="/dev/sda5">/</mountpoint>
       <mountpoint dev="/dev/sda3">/usr</mountpoint>

inspector/expected-debian.img.xml

@@ -11,6 +11,7 @@
     <package_format>deb</package_format>
     <package_management>apt</package_management>
     <hostname>debian.invalid</hostname>
+    <osinfo>debian5</osinfo>
     <mountpoints>
       <mountpoint dev="/dev/debian/root">/</mountpoint>
       <mountpoint dev="/dev/debian/usr">/usr</mountpoint>

inspector/expected-fedora.img.xml

@@ -11,6 +11,7 @@
     <package_format>rpm</package_format>
     <package_management>yum</package_management>
     <hostname>fedora.invalid</hostname>
+    <osinfo>fedora14</osinfo>
     <mountpoints>
       <mountpoint dev="/dev/VG/Root">/</mountpoint>
       <mountpoint dev="/dev/sda1">/boot</mountpoint>

inspector/expected-ubuntu.img.xml

@@ -11,6 +11,7 @@
     <package_format>deb</package_format>
     <package_management>apt</package_management>
     <hostname>ubuntu.invalid</hostname>
+    <osinfo>ubuntu10.10</osinfo>
     <mountpoints>
       <mountpoint dev="/dev/sda2">/</mountpoint>
       <mountpoint dev="/dev/sda1">/boot</mountpoint>

inspector/inspector.c

@@ -443,6 +443,13 @@ output_root (xmlTextWriterPtr xo, char *root)
 					 BAD_CAST str));
   free (str);
 
+  str = guestfs_inspect_get_osinfo (g, root);
+  if (!str) exit (EXIT_FAILURE);
+  if (STRNEQ (str, "unknown"))
+    XMLERROR (-1,
+              xmlTextWriterWriteElement (xo, BAD_CAST "osinfo", BAD_CAST str));
+  free (str);
+
   output_mountpoints (xo, root);
 
   output_filesystems (xo, root);

inspector/virt-inspector.rng

@@ -38,6 +38,7 @@
             <optional><ref name="ospackageformat"/></optional>
             <optional><ref name="ospackagemanagement"/></optional>
             <optional><element name="hostname"><text/></element></optional>
+            <optional><element name="osinfo"><text/></element></optional>
 
             <ref name="mountpoints"/>
             <ref name="filesystems"/>