[check] Small changes in Make file.

check/GNUmakefile

+### Uncomment if Check was installed via package manager 
+#CHECK_LIB     = -lcheck
+
+### Uncomment and adapt if Check was installed manually
 CHECKROOT     = /informatik/home/hovy/scratch/lib/check
-CHECK_INCLUDE = -I$(CHECKROOT)/include
 CHECK_LIB     = -L$(CHECKROOT)/lib/libcheck.a -lcheck
 
 VPATH         = ../src