test: support coreutils built with --enable-single-binary=symlinks

Alpine/postmarketOS build coreutils with --enable-single-binary=symlinks.
In that case, all commands provided by coreutils are symlink to
/usr/bin/coreutils, and it calls prctl(PR_SET_NAME, argv[0]), hence the comm
will be the path to the symlink.

This also makes not kill sleep command with SIGKILL in TEST-17-UDEV, that is
totally unnecessary.

test/integration-tests/TEST-59-RELOADING-RESTART/meson.build

@@ -3,6 +3,6 @@
 integration_tests += [
         integration_test_template + {
                 'name' : fs.name(meson.current_source_dir()),
-                'coredump-exclude-regex' : '/(sleep|bash|systemd-notify)$',
+                'coredump-exclude-regex' : '/(coreutils|sleep|bash|systemd-notify)$',
         },
 ]