Commit 97f40301 changed warning messages from

    timestamp-if-enabled progname ":" location "warning: " message

to

    "warning: " timestamp-if-enabled progname ":" location message

This regressed qemu-iotests 051.  Put "warning: " right back where it
was, along with "info: ".
Reported-by: NKevin Wolf <kwolf@redhat.com>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1500449614-16811-1-git-send-email-armbru@redhat.com>
Reviewed-by: NAlistair Francis <alistair.francis@xilinx.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>