x86/unwind/orc: Fix error path for bad ORC entry type

commit a0f81bf2 upstream.

If the ORC entry type is unknown, nothing else can be done other than
reporting an error.  Exit the function instead of breaking out of the
switch statement.

Fixes: ee9f8fce

 ("x86/unwind: Add the ORC unwinder")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/a7fa668ca6eabbe81ab18b2424f15adbbfdc810a.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>