objtool: Add a missing comma to avoid string concatenation

Recently the kbuild robot reported two new errors:

>> lib/kunit/kunit-example-test.o: warning: objtool: .text.unlikely: unexpected end of section
>> arch/x86/kernel/dumpstack.o: warning: objtool: oops_end() falls through to next function show_opcodes()

I don't know why they did not occur in my test setup but after digging
it I realized I had accidentally dropped a comma in
tools/objtool/check.c when I renamed rewind_stack_do_exit to
rewind_stack_and_make_dead.

Add that comma back to fix objtool errors.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 0e25498f8c ("exit: Add and use make_task_dead.")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>

tools/objtool/check.c

@@ -177,7 +177,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"fortify_panic",
 		"usercopy_abort",
 		"machine_real_restart",
-		"rewind_stack_and_make_dead"
+		"rewind_stack_and_make_dead",
 		"kunit_try_catch_throw",
 		"xen_start_kernel",
 		"cpu_bringup_and_idle",