ceph: fix spelling mistake: "enabing" -> "enabling"

trivial fix to spelling mistake in debug message

Signed-off-by: Colin Ian King <[e-mail]>
Signed-off-by: Yan, Zheng <[e-mail]>

fs/ceph/cache.c

···
 		fscache_enable_cookie(ci->fscache, ceph_fscache_can_enable,
 				inode);
 		if (fscache_cookie_enabled(ci->fscache)) {
-			dout("fscache_file_set_cookie %p %p enabing cache\n",
+			dout("fscache_file_set_cookie %p %p enabling cache\n",
 			     inode, filp);
 		}
 	}