Fix deadlock in socket code

Fix a deadlock that was introduced in 555745c
and that happens on platforms without recursive locks (e.g. esp32) by removing
an unnessary lock in `socket_recv`.

Signed-off-by: Paul Guyot <pguyot@kallisys.net>

Author: pguyot

src/libAtomVM/otp_socket.c

@@ -1820,9 +1820,7 @@ static ssize_t do_socket_recv(struct SocketResource *rsrc_obj, uint8_t *buf, siz
 
 ssize_t socket_recv(struct SocketResource *rsrc_obj, uint8_t *buf, size_t len, int flags, term *from, Heap *heap)
 {
-    SMP_RWLOCK_RDLOCK(rsrc_obj->socket_lock);
     ssize_t result = do_socket_recv(rsrc_obj, buf, len, flags, from, heap);
-    SMP_RWLOCK_UNLOCK(rsrc_obj->socket_lock);
     return result;
 }