smartcard: spell ccid-card-emulated qemu property correctly

Reported by Anthony Messina in
https://bugzilla.redhat.com/show_bug.cgi?id=904692
Present since introduction of smartcard support in commit f5fd9baa

* src/qemu/qemu_command.c (qemuBuildCommandLine): Match qemu spelling.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-host-certificates.args:
Fix broken test.

src/qemu/qemu_command.c

@@ -6846,7 +6846,7 @@ qemuBuildCommandLine(virConnectPtr conn,
             } else {
                 database = VIR_DOMAIN_SMARTCARD_DEFAULT_DATABASE;
             }
-            virBufferAsprintf(&opt, ",database=%s", database);
+            virBufferAsprintf(&opt, ",db=%s", database);
             break;
 
         case VIR_DOMAIN_SMARTCARD_TYPE_PASSTHROUGH:

tests/qemuxml2argvdata/qemuxml2argv-smartcard-host-certificates.args

@@ -4,5 +4,5 @@ socket,id=charmonitor,path=/tmp/test-monitor,server,nowait -mon \
 chardev=charmonitor,id=monitor,mode=readline -no-acpi -boot c -device \
 usb-ccid,id=ccid0 -usb -device \
 ccid-card-emulated,backend=certificates,cert1=cert1,cert2=cert2,cert3=cert3\
-,database=/etc/pki/nssdb,id=smartcard0,bus=ccid0.0 -device \
+,db=/etc/pki/nssdb,id=smartcard0,bus=ccid0.0 -device \
 virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3