qemu: change rbd auth_supported separation character to ;

This works with newer qemu that doesn't allow escaping spaces.
It's backwards compatible as well.
Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>
(cherry picked from commit d50cae33)

src/qemu/qemu_command.c

@@ -1674,7 +1674,7 @@ qemuBuildRBDString(virConnectPtr conn,
                 goto error;
             }
             virBufferEscape(opt, '\\', ":",
-                            ":key=%s:auth_supported=cephx none",
+                            ":key=%s:auth_supported=cephx\\;none",
                             base64);
             VIR_FREE(base64);
         } else {

tests/qemuxml2argvdata/qemuxml2argv-disk-drive-network-rbd-auth.args

@@ -5,6 +5,6 @@ file=/dev/HostVG/QEMUGuest1,if=ide,bus=0,unit=0 -drive \
 file=rbd:pool/image:\
 id=myname:\
 key=QVFDVm41aE82SHpGQWhBQXEwTkN2OGp0SmNJY0UrSE9CbE1RMUE=:\
-auth_supported=cephx none:\
+auth_supported=cephx\;none:\
 mon_host=mon1.example.org\:6321\;mon2.example.org\:6322\;mon3.example.org\:6322,\
 if=virtio,format=raw -net none -serial none -parallel none -usb