Consolidate both versions of tr_isPex into a single function.

There used to be two versions of tr_isPex; one correct in peer-mgr.c,
and one buggy in resume.c.  The buggy version caused us to reject all
peers with non-trivial flags when resuming.

libtransmission/peer-mgr.c

@@ -1766,12 +1766,6 @@ tr_peerMgrAddIncoming( tr_peerMgr * manager,
     managerUnlock( manager );
 }
 
-static tr_bool
-tr_isPex( const tr_pex * pex )
-{
-    return pex && tr_isAddress( &pex->addr );
-}
-
 void
 tr_peerMgrAddPex( tr_torrent * tor, uint8_t from,
                   const tr_pex * pex, int8_t seedProbability )

libtransmission/peer-mgr.h

@@ -131,6 +131,12 @@ typedef struct tr_peer
 }
 tr_peer;
 
+static inline tr_bool
+tr_isPex( const tr_pex * pex )
+{
+    return pex && tr_isAddress( &pex->addr );
+}
+
 const tr_address * tr_peerAddress( const tr_peer * );
 
 int tr_pexCompare( const void * a, const void * b );

libtransmission/resume.c

@@ -103,13 +103,6 @@ savePeers( tr_benc * dict, const tr_torrent * tor )
     tr_free( pex );
 }
 
-static tr_bool
-tr_isPex( const tr_pex * pex )
-{
-    return tr_isAddress( &pex->addr )
-        && ( pex->flags & 3 ) == pex->flags;
-}
-
 static int
 addPeers( tr_torrent * tor, const uint8_t * buf, int buflen )
 {