Makefile: Fix build of utest on systems with --as-needed enabled

On systems (such as ALT Linux) where `--as-needed' is passed to ld by
default, building tests fail due to CUNIT_INSTALLED test failure to link
with libcunit, becasue `-lcunit' is passed before input file (which is
`-'). Move `-lcunit' after '-' to link it properly.

To reproduce `make CC='gcc -Wl,--as-needed' test`. Error message:

  Makefile:344: *** CUnit framework not installed, cannot build unit tests.  Stop.

Link: https://lore.kernel.org/linux-trace-devel/20200720164453.5161-2-vt@altlinux.org

Cc: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/Makefile b/Makefile
index 6b606da..83e5646 100644
--- a/Makefile
+++ b/Makefile
@@ -242,7 +242,7 @@
 CFLAGS += -DVSOCK
 endif
 
-CUNIT_INSTALLED := $(shell if (printf "$(pound)include <CUnit/Basic.h>\n void main(){CU_initialize_registry();}" | $(CC) -x c -lcunit - >/dev/null 2>&1) ; then echo 1; else echo 0 ; fi)
+CUNIT_INSTALLED := $(shell if (printf "$(pound)include <CUnit/Basic.h>\n void main(){CU_initialize_registry();}" | $(CC) -x c - -lcunit >/dev/null 2>&1) ; then echo 1; else echo 0 ; fi)
 export CUNIT_INSTALLED
 
 export CFLAGS