selftests/ublk: fix Makefile to rebuild on header changes

Add header dependencies to kublk build rule so that changes to
kublk.h, ublk_dep.h, or utils.h trigger a rebuild.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Ming Lei

tools/testing/selftests/ublk/Makefile

@@ -51,10 +51,10 @@ TEST_PROGS += test_stress_07.sh
 
 TEST_GEN_PROGS_EXTENDED = kublk
 
+LOCAL_HDRS += $(wildcard *.h)
 include ../lib.mk
 
-$(TEST_GEN_PROGS_EXTENDED): kublk.c null.c file_backed.c common.c stripe.c \
-	fault_inject.c
+$(TEST_GEN_PROGS_EXTENDED): $(wildcard *.c)
 
 check:
 	shellcheck -x -f gcc *.sh