RDMA/cma: Fix truncation compilation warning in make_cma_ports

RDMA/cma: Fix truncation compilation warning in make_cma_ports

The following compilation error is false alarm as RDMA devices don't
have such large amount of ports to actually cause to format truncation.

drivers/infiniband/core/cma_configfs.c: In function ‘make_cma_ports’:
drivers/infiniband/core/cma_configfs.c:223:57: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
  223 |                 snprintf(port_str, sizeof(port_str), "%u", i + 1);
      |                                                         ^
drivers/infiniband/core/cma_configfs.c:223:17: note: ‘snprintf’ output between 2 and 11 bytes into a destination of size 10
  223 |                 snprintf(port_str, sizeof(port_str), "%u", i + 1);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[5]: *** [scripts/Makefile.build:243: drivers/infiniband/core/cma_configfs.o] Error 1

Fixes: 045959db65c6 ("IB/cma: Add configfs for rdma_cm")
Link: https://lore.kernel.org/r/a7e3b347ee134167fa6a3787c56ef231a04bc8c2.1694434639.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>