[yocto] [matchbox-wm][PATCH v2] configure.ac: add lib math for composite enabled builds

[Awais Belal]

The composite enabled builds require lib math to be
present on the linker command line otherwise we get
ld: composite-engine.o: undefined reference to symbol 'exp@@GLIBC_2.2.5'
during compilation.

Signed-off-by: Awais Belal <awais_belal at mentor.com>
---
 configure.ac | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configure.ac b/configure.ac
index dce82cc..a3e384f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -248,6 +248,7 @@ dnl ------ Composite -------------------------------------------------------
 if test x$enable_composite != xno; then
   PKG_CHECK_MODULES(COMPO, xcomposite xfixes xdamage xrender, ,
 			   AC_MSG_ERROR([*** Required Composite Librays not installed ***]))
+  COMPO_LIBS="$COMPO_LIBS -lm"
 
   AC_DEFINE(USE_COMPOSITE, [1], [use bleeding enge composite code])
 
-- 
2.7.4