x86/vdso: Add missing brackets in switch case

0-day reported:

  arch/x86/entry/vdso/vma.c:199:3: warning: label followed by a declaration
  				 	    is a C23 extension [-Wc23-extensions]

Add the missing brackets.

Fixes: e93d252 ("x86/vdso: Split virtual clock pages into dedicated mapping")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel.org/oe-kbuild-all/202411022359.fBPFTg2T-lkp@intel.com/

Author: KAGA-KOKO

arch/x86/entry/vdso/vma.c

@@ -196,21 +196,26 @@ static vm_fault_t vvar_vclock_fault(const struct vm_special_mapping *sm,
 	switch (vmf->pgoff) {
 #ifdef CONFIG_PARAVIRT_CLOCK
 	case VDSO_PAGE_PVCLOCK_OFFSET:
+	{
 		struct pvclock_vsyscall_time_info *pvti =
 			pvclock_get_pvti_cpu0_va();
+
 		if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK))
 			return vmf_insert_pfn_prot(vma, vmf->address,
 					__pa(pvti) >> PAGE_SHIFT,
 					pgprot_decrypted(vma->vm_page_prot));
 		break;
+	}
 #endif /* CONFIG_PARAVIRT_CLOCK */
 #ifdef CONFIG_HYPERV_TIMER
 	case VDSO_PAGE_HVCLOCK_OFFSET:
+	{
 		unsigned long pfn = hv_get_tsc_pfn();
 
 		if (pfn && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
 			return vmf_insert_pfn(vma, vmf->address, pfn);
 		break;
+	}
 #endif /* CONFIG_HYPERV_TIMER */
 	}