nilfs2: fix typo "numer" -> "number" in alloc.c

Fixes the typo found in a warning message of a persistent object
allocator function.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/alloc.c

@@ -425,7 +425,7 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode,
 	bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
 	if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
 				    group_offset, bitmap))
-		printk(KERN_WARNING "%s: entry numer %llu already freed\n",
+		printk(KERN_WARNING "%s: entry number %llu already freed\n",
 		       __func__, (unsigned long long)req->pr_entry_nr);
 
 	nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);