tipc: remove pointless name sanity check and tipc_alphabet array

There is no real reason to check whether all letters in the given
media name and network interface name are within the character set
defined in tipc_alphabet array. Even if we eliminate the checking,
the rest of checking conditions in tipc_enable_bearer() can ensure
we do not enable an invalid or illegal bearer.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 1c1e615..a79c755 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -210,9 +210,7 @@
 	    (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
 	    (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
 	    (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
-	    (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME) ||
-	    (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
-	    (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
+	    (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME))
 		return 0;
 
 	/* return link name components, if necessary */