net/mlx5: hw counters: Use kvmalloc for bulk query buffer

The bulk query buffer starts out small (see [1]) and as soon as the
number of counters goes past the initial threshold grows to max
size (32K entries, 512KB) with a retry scheme.

This commit switches to using kvmalloc for the buffer, which has a near
zero likelihood of failing, and thus the explicit retry scheme becomes
superfluous and is taken out. On the low chance the allocation fails, it
will still be retried every sampling_interval, when the wq task runs.

[1] commit b247f32a ("net/mlx5: Dynamically resize flow counters
query buffer")

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20241001103709.58127-3-tariqt@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>