hv_netvsc: Allocate memory in netvsc_dma_map() with GFP_ATOMIC

hv_netvsc: Allocate memory in netvsc_dma_map() with GFP_ATOMIC

Memory allocations in the network transmit path must use GFP_ATOMIC
so they won't sleep.

Reported-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/lkml/8a4d08f94d3e6fe8b6da68440eaa89a088ad84f9.camel@redhat.com/
Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1675714317-48577-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>