x86/xen: Fix typo in xen_pagetable_p2m_free()

Fix typo in xen_pagetable_p2m_free(): s/Fortunatly/Fortunately
Signed-off-by: Hui Su <sh_def@163.com>
Link: https://lore.kernel.org/r/20200927172836.GA7423@rlk

[boris: reword commit message slightly]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

arch/x86/xen/mmu_pv.c

@@ -1149,7 +1149,7 @@ static void __init xen_pagetable_p2m_free(void)
 	 * We could be in __ka space.
 	 * We roundup to the PMD, which means that if anybody at this stage is
 	 * using the __ka address of xen_start_info or
-	 * xen_start_info->shared_info they are in going to crash. Fortunatly
+	 * xen_start_info->shared_info they are in going to crash. Fortunately
 	 * we have already revectored in xen_setup_kernel_pagetable.
 	 */
 	size = roundup(size, PMD_SIZE);