systemd syntax update

Author: lilydjwg

after/syntax/systemd.vim

@@ -28,7 +28,7 @@ syn match sdOctal    contained nextgroup=sdErr /0\o\{3,4}/
 syn match sdDuration contained nextgroup=sdErr /\d\+/
 syn match sdDuration contained nextgroup=sdErr /\%(\d\+\s*\%(usec\|msec\|seconds\=\|minutes\=\|hours\=\|days\=\|weeks\=\|months\=\|years\=\|us\|ms\|sec\|min\|hr\|[smhdwMy]\)\s*\)\+/
 syn match sdDatasize contained nextgroup=sdErr /\d\+[KMGT]/
-syn match sdFilename contained nextgroup=sdErr /\/\S*/
+syn match sdFilename contained nextgroup=sdErr /\%(%h\)\?\/\S*/
 syn match sdPercent  contained nextgroup=sdErr /\d\+%/
 syn keyword sdBool   contained nextgroup=sdErr 1 yes true on 0 no false off
 syn match sdUnitName contained /\S\+\.\(automount\|mount\|swap\|socket\|service\|target\|path\|timer\|device\|slice\|scope\)\_s/