help: dd missing newline

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

qemu-options.hx

diff --git a/qemu-options.hx b/qemu-options.hx
index 739894d..166eae6 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3513,7 +3513,7 @@
     "                Output vmstate information in JSON format to file.\n"
     "                Use the scripts/vmstate-static-checker.py file to\n"
     "                check for possible regressions in migration code\n"
-    "                by comparing two such vmstate dumps.",
+    "                by comparing two such vmstate dumps.\n",
     QEMU_ARCH_ALL)
 STEXI
 @item -dump-vmstate @var{file}