IB/IPoIB: Convert IPoIB to memalloc_noio_* calls

IB/IPoIB: Convert IPoIB to memalloc_noio_* calls

Commit b756b72e2a44 ("mm: teach mm by current context info to not do I/O
during memory allocation") added the memalloc_noio_(save|restore) functions
to enable people to modify the MM behavior by disabling I/O during memory
allocation. This was further extended in Fixes: 0f7e1aa748fe ("mm: clear
__GFP_FS when PF_MEMALLOC_NOIO is set"). memalloc_noio_* functions prevent
allocation paths recursing back into the filesystem without explicitly
changing the flags for every allocation site.

However the IPoIB hasn't been keeping up with the changes and missed
completely these memalloc_noio_* calls. This led to update of
allocation site with special QP creation flag, see commit 0e203157d904
("IB: Add a QP creation flag to use GFP_NOIO allocations"), while this
flag is supported by small number of drivers in IB stack.

Let's change it by updating to memalloc_noio_* calls and allow
for every driver underneath enjoy NOIO allocations.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>