livepatch: Remove reliable stacktrace check in klp_try_switch_task()

Support for immediate flag was removed by commit d0807da78e11
("livepatch: Remove immediate feature").  We bail out during
patch registration for architectures, those don't support
reliable stack trace. Remove the check in klp_try_switch_task(),
as its not required.

Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kernel/livepatch/transition.c

@@ -309,13 +309,6 @@ static bool klp_try_switch_task(struct task_struct *task)
 	if (task->patch_state == klp_target_state)
 		return true;
 
-	/*
-	 * For arches which don't have reliable stack traces, we have to rely
-	 * on other methods (e.g., switching tasks at kernel exit).
-	 */
-	if (!klp_have_reliable_stack())
-		return false;
-
 	/*
 	 * Now try to check the stack for any to-be-patched or to-be-unpatched
 	 * functions.  If all goes well, switch the task to the target patch