Revert "TEST-55-OOMD: workaround for kernel regression in 6.12-rcX"

This reverts commit 88bbf187a9.

The kernel regression has been hopefully fixed by
https://github.com/torvalds/linux/commit/c6508124193d42bbc3224571eb75bfa4c1821fbb
which is included in 6.12-rc4.
Let's drop the workaround.

test/units/TEST-55-OOMD.sh

@@ -95,21 +95,6 @@ else
     systemd-run -t -p MemoryMax=10M -p MemorySwapMax=0 -p MemoryZSwapMax=0 /bin/true
 fi
 
-check_killed() {
-    local unit="${1:?}"
-    shift
-
-    systemctl "$@" status "$unit" || return 0 # Yay! The service has been expectedly killed.
-
-    # Workaround for the regression in kernel 6.12-rcX, explained in issue #32730.
-    if journalctl --no-hostname -k -t kernel --grep 'psi: inconsistent task state!'; then
-        echo "$unit is unexpectedly still alive, and inconsistency in PSI is reported by the kernel, skipping." >/skipped
-        exit 77
-    fi
-
-    return 1 # Huh? Something borked.
-}
-
 test_basic() {
     local cgroup_path="${1:?}"
     shift
@@ -136,7 +121,7 @@ test_basic() {
     done
 
     # testbloat should be killed and testchill should be fine
-    if ! check_killed TEST-55-OOMD-testbloat.service "$@"; then exit 42; fi
+    if systemctl "$@" status TEST-55-OOMD-testbloat.service; then exit 42; fi
     if ! systemctl "$@" status TEST-55-OOMD-testchill.service; then exit 24; fi
 
     systemctl "$@" kill --signal=KILL TEST-55-OOMD-testbloat.service || :
@@ -187,7 +172,7 @@ EOF
 
     # testmunch should be killed since testbloat had the avoid xattr on it
     if ! systemctl status TEST-55-OOMD-testbloat.service; then exit 25; fi
-    if ! check_killed TEST-55-OOMD-testmunch.service; then exit 43; fi
+    if systemctl status TEST-55-OOMD-testmunch.service; then exit 43; fi
     if ! systemctl status TEST-55-OOMD-testchill.service; then exit 24; fi
 
     systemctl kill --signal=KILL TEST-55-OOMD-testbloat.service || :
@@ -263,7 +248,7 @@ EOF
         sleep 2
     done
 
-    if ! check_killed TEST-55-OOMD-testmunch.service; then exit 44; fi
+    if systemctl status TEST-55-OOMD-testmunch.service; then exit 44; fi
     if ! systemctl status TEST-55-OOMD-testchill.service; then exit 23; fi
 
     systemctl kill --signal=KILL TEST-55-OOMD-testmunch.service || :