qemu: free SEV caps in virQEMUCapsDispose

Commit 77f51ab5 started parsing an copying the SEV capabilities,
but omitted the free call.
Signed-off-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_capabilities.c

@@ -1662,6 +1662,8 @@ void virQEMUCapsDispose(void *obj)
 
     VIR_FREE(qemuCaps->gicCapabilities);
 
+    virSEVCapabilitiesFree(qemuCaps->sevCapabilities);
+
     virQEMUCapsHostCPUDataClear(&qemuCaps->kvmCPU);
     virQEMUCapsHostCPUDataClear(&qemuCaps->tcgCPU);
 }