selftests: lib.mk: fix test executable status check to use full path

Fix test executable status check to use full path for make O=dir case,m
when tests are relocated to user specified object directory. Without the
full path, this check fails to find the file and fails the test.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/lib.mk

@@ -21,7 +21,7 @@ define RUN_TESTS
 		test_num=`echo $$test_num+1 | bc`;	\
 		echo "selftests: $$BASENAME_TEST";	\
 		echo "========================================";	\
-		if [ ! -x $$BASENAME_TEST ]; then	\
+		if [ ! -x $$TEST ]; then	\
 			echo "selftests: Warning: file $$BASENAME_TEST is not executable, correct this.";\
 			echo "not ok 1..$$test_num selftests: $$BASENAME_TEST [FAIL]"; \
 		else					\