qemu: agent: fix potential leak in qemuAgentGetFSInfo()

On error paths, info_ret could potentially leak. Make sure it's freed.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

src/qemu/qemu_agent.c

@@ -2208,6 +2208,7 @@ qemuAgentGetFSInfo(qemuAgentPtr mon,
             virDomainFSInfoFree(info_ret[i]);
     }
     VIR_FREE(agentinfo);
+    VIR_FREE(info_ret);
     return ret;
 }