lib: Fix docs generated for enum virDomainBlockJobType

Mixing documentation strings trailing the enum value and preceeding the
enum value ends in a big mixup. Fix docs string for
VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN so that it's not squished together
with the next one.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

include/libvirt/libvirt-domain.h

@@ -2375,7 +2375,8 @@ int virDomainSetPerfEvents(virDomainPtr dom,
  * Describes various possible block jobs.
  */
 typedef enum {
-    VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN = 0, /* Placeholder */
+    /* Placeholder */
+    VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN = 0,
 
     /* Block Pull (virDomainBlockPull, or virDomainBlockRebase without
      * flags), job ends on completion */