Fix sys_ipc() SEMCTL on sparc64.

Fix sys_ipc() SEMCTL on sparc64.

changeset 6536a6b331d3225921c398eb7c6e4ecedb9b05e0 from mainline

Thanks to Tom Callaway for the excellent bug report and
test case.

sys_ipc() has several problems, most to due with semaphore
call handling:

1) 'err' return should be a 'long'
2) "union semun" is passed in a register on 64-bit compared
   to 32-bit which provides it on the stack and therefore
   by reference
3) Second and third arguments to SEMCTL are swapped compared
   to 32-bit.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>