directfb-examples: Fix building with new autoconf
This fixes the following build error:
,----
| .../configure: line 4229: syntax error near unexpected token `DIRECTFB,'
| .../configure: line 4229: `PKG_CHECK_MODULES(DIRECTFB, directfb >= $DIRECTFB_REQUIRED_VERSION, WATER=`$PKG_CONFIG --variable=water directfb` ,'
`----
(From OE-Core rev: 3f7fcbc167c13bdaa6c12a81c7851530d72f02e0)
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>