RDMA/rtrs: Get rid of the do_next_path while_next_path macros

RDMA/rtrs: Get rid of the do_next_path while_next_path macros

The macros do_each_path/while_each_path lead to a smatch warning:

drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting

Also checkpatch complains:
ERROR: Macros with multiple statements should be enclosed in a do - while loop

The macros are used only in two places: for a normal IO path and for the
failover path triggered after errors.

Get rid of the macros and just use a for loop iterating over the list of
paths in both places. It is easier to read and also less lines of code.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20200522053924.528980-1-danil.kipnis@cloud.ionos.com
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>