x86/paravirt: Mark unused patch_default label

A bugfix commit:

45dbea5f55c0 ("x86/paravirt: Fix native_patch()")

... introduced a harmless warning:

arch/x86/kernel/paravirt_patch_32.c: In function 'native_patch':
arch/x86/kernel/paravirt_patch_32.c:71:1: error: label 'patch_default' defined but not used [-Werror=unused-label]

Fix it by annotating the label as __maybe_unused.

Reported-by: Arnd Bergmann <[e-mail]>
Reported-by: Piotr Gregor <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Brian Gerst <[e-mail]>
Cc: Denys Vlasenko <[e-mail]>
Cc: H. Peter Anvin <[e-mail]>
Cc: Josh Poimboeuf <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Fixes: 45dbea5f55c0 ("x86/paravirt: Fix native_patch()")
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/kernel/paravirt_patch_32.c

···
 #endif
 
 	default:
-patch_default:
+patch_default: __maybe_unused
 		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
 		break;
 

arch/x86/kernel/paravirt_patch_64.c

···
 #endif
 
 	default:
-patch_default:
+patch_default: __maybe_unused
 		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
 		break;