cpu_x86: Fix memory leak - virCPUx86GetHost

Commit 56b254dcc called virCPUx86DataAdd, but returned -1 directly
without calling the virCPUx86DataFree.

Found by Coverity.

Signed-off-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/cpu/cpu_x86.c

@@ -2791,7 +2791,7 @@ virCPUx86GetHost(virCPUDefPtr cpu,
             };
 
             if (virCPUx86DataAdd(cpuData, &item) < 0)
-                return -1;
+                goto cleanup;
         }
     }