Fix SuiteSparse3 UFConfig.h detection really.

Change-Id: Id187102e755b7d778dff4363f22f9a4697ed12dd

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f410ea5..0244260 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -220,7 +220,7 @@
 
 FIND_PATH(UFCONFIG_INCLUDE
           NAMES UFconfig.h
-          PATHS ${SUITESPARSE_SEARCH_INCLUDE})
+          PATHS ${SUITESPARSE_SEARCH_HEADERS})
 IF (EXISTS ${UFCONFIG_INCLUDE})
   MESSAGE("-- Found UFconfig header in: ${UFCONFIG_INCLUDE}")
 ELSE (EXISTS ${UFCONFIG_INCLUDE})