configure: add xcb cflags and extralibs to cflags and extralibs.

Replace xcb_event by xcb, as the former is no more used and the latter
is needed on configurations where only xcb is available, and not
libxcb_shm and/or libxcb_xfixes.
Signed-off-by: NBenoit Fouet <benoit.fouet@free.fr>
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

configure

@@ -5040,8 +5040,8 @@ if enabled libxcb; then
             enabled libxcb_xfixes && die "ERROR: libxcb_xfixes not found";
         } && enable libxcb_xfixes; }
 
-    add_cflags $xcb_event_cflags $xcb_shm_cflags $xcb_xfixes_cflags
-    add_extralibs $xcb_event_libs $xcb_shm_libs $xcb_xfixes_libs
+    add_cflags $xcb_cflags $xcb_shm_cflags $xcb_xfixes_cflags
+    add_extralibs $xcb_libs $xcb_shm_libs $xcb_xfixes_libs
 fi
 fi