[PATCH] selftests/kexec: fix test_kexec_jump build and ignore generated binary

[Moon Hee Lee <moonhee.lee.ca@gmail.com>]

The test_kexec_jump program builds correctly when invoked from the top-level
selftests/Makefile, which explicitly sets the OUTPUT variable. However,
building directly in tools/testing/selftests/kexec fails with:

  make: *** No rule to make target '/test_kexec_jump', needed by 'test_kexec_jump.sh'.  Stop.

This failure occurs because the Makefile rule relies on $(OUTPUT), which is
undefined in direct builds.

Fix this by listing test_kexec_jump in TEST_GEN_PROGS, the standard way to
declare generated test binaries in the kselftest framework. This ensures the
binary is built regardless of invocation context and properly removed by
make clean.

Also add the binary to .gitignore to avoid tracking it in version control.

Signed-off-by: Moon Hee Lee <moonhee.lee.ca@gmail.com>
---
 tools/testing/selftests/kexec/.gitignore | 2 ++
 tools/testing/selftests/kexec/Makefile   | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/kexec/.gitignore

diff --git a/tools/testing/selftests/kexec/.gitignore b/tools/testing/selftests/kexec/.gitignore
new file mode 100644
index 000000000000..5f3d9e089ae8
--- /dev/null
+++ b/tools/testing/selftests/kexec/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+test_kexec_jump
diff --git a/tools/testing/selftests/kexec/Makefile b/tools/testing/selftests/kexec/Makefile
index e3000ccb9a5d..874cfdd3b75b 100644
--- a/tools/testing/selftests/kexec/Makefile
+++ b/tools/testing/selftests/kexec/Makefile
@@ -12,7 +12,7 @@ include ../../../scripts/Makefile.arch
 
 ifeq ($(IS_64_BIT)$(ARCH_PROCESSED),1x86)
 TEST_PROGS += test_kexec_jump.sh
-test_kexec_jump.sh: $(OUTPUT)/test_kexec_jump
+TEST_GEN_PROGS := test_kexec_jump
 endif
 
 include ../lib.mk
-- 
2.43.0