[mutter] Typo fix: missing '\'

[Emmanuele Bassi <ebassi src gnome org>]

commit c76eedd794051b79456ba331e9595af6dd3490e2
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sun Apr 30 15:05:52 2017 +0100

    Typo fix: missing '\'
    
    Without the backslash, the build breaks.

 clutter/clutter/Makefile.am.marshal |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/clutter/clutter/Makefile.am.marshal b/clutter/clutter/Makefile.am.marshal
index b6fc896..f29629c 100644
--- a/clutter/clutter/Makefile.am.marshal
+++ b/clutter/clutter/Makefile.am.marshal
@@ -43,7 +43,7 @@ $(marshal_h): stamp-marshal
        @true
 
 $(marshal_c): $(marshal_h)
-       $(AM_V_GEN)$(GLIB_GENMARSHAL)
+       $(AM_V_GEN)$(GLIB_GENMARSHAL) \
                --prefix=$(glib_marshal_prefix) \
                --body \
        $(marshal_list) > xgen-mc \