ocs_fc: Fix use after free bug in ocs_hw_async_call()

Freed ctx is used in the later callee ocs_hw_command(),
which is a use after free bug.

Return error if sli_cmd_common_nop() failed.

PR: 255865
Reported by: lylgood@foxmail.com
Approved by:: markj

(cherry picked from commit 7377d3831bc8abec2d6e5fee359d7383d4551feb)