net: axi_emac: Fix parentheses around operand !

net: axi_emac: Fix parentheses around operand !

Fix these compilation warning by proper grouping:
In function 'axi_dma_init': drivers/net/xilinx_axi_emac.c:391:7:
warning: suggest parentheses around operand of '!' or change '&' to '&&'
or '!' to '~' [-Wparentheses]
    if (!(in_be32(&priv->dmatx->control) |
        ^
In function 'axiemac_send': drivers/net/xilinx_axi_emac.c:501:21:
warning: suggest parentheses around operand of '!' or change '&' to '&&'
or '!' to '~' [-Wparentheses]
  while (timeout && (!in_be32(&priv->dmatx->status) &

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>