lsipc: fix semaphore USED counter

lsipc: fix semaphore USED counter

The code incorrectly counts only with the first item in the linked
list (due to a typo). It seems rather fragile to use "semds" and
"semdsp" as variable names in the same code ...

 # lsipc -gs

Old:

 KEY ID PERMS OWNER NSEMS RESOURCE DESCRIPTION                                LIMIT USED  USE%
                          SEMMNI   Number of semaphore identifiers            32000    3 0.01%
                          SEMMNS   Total number of semaphores            1024000000  369 0.00%
                          SEMMSL   Max semaphores per semaphore set.          32000    -     -
                          SEMOPM   Max number of operations per semop(2)        500    -     -
                          SEMVMX   Semaphore max value                        32767    -     -

Fixed:

 KEY ID PERMS OWNER NSEMS RESOURCE DESCRIPTION                                LIMIT USED  USE%
                          SEMMNI   Number of semaphore identifiers            32000    3 0.01%
                          SEMMNS   Total number of semaphores            1024000000  156 0.00%
                          SEMMSL   Max semaphores per semaphore set.          32000    -     -
                          SEMOPM   Max number of operations per semop(2)        500    -     -
                          SEMVMX   Semaphore max value                        32767    -     -

Addresses: https://issues.redhat.com/browse/RHEL-30269
Signed-off-by: Karel Zak <kzak@redhat.com>