prctl: remove redunant assignment of "error" to zero

prctl: remove redunant assignment of "error" to zero

Just setting the "error" to error number is enough on failure and It
doesn't require to set "error" variable to zero in each switch case, since
it was already initialized with zero.  And also removed return 0 in switch
case with break statement

Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>