ssa.c Improve lockf result handling in ssa_open_lock_file

From lockf man page:
 EACCES or EAGAIN
              The file is locked and F_TLOCK or F_TEST was specified, or the
              operation is prohibited because the file has been memory-
              mapped by another process.

Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>