clean-includes: Add glib.h to list of unneeded includes

clean-includes: Add glib.h to list of unneeded includes

osdep.h pulls in glib.h via glib-compat.h, so add it to the list of
includes that we remove. (This then means we must avoid running
clean-includes on glib-compat.h or it will delete the glib.h include.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>