[gvfs] build: Use install prefix in systemd files paths

[Ondrej Holy <oholy src gnome org>]

commit 1e2867efe1e5cdb1d64b2ac11a589bd87f924121
Author: Diego Escalante Urrelo <diegoe gnome org>
Date:   Sun Apr 18 06:02:31 2021 -0500

    build: Use install prefix in systemd files paths
    
    When installing gvfs into a prefix (like in jhbuild), we need to pass
    `gvfs_prefix` to meson's `get_pkgconfig_variable` to make sure that
    systemd unit files are installed to the installation prefix, instead of
    systemd's prefix (which will likely be your system's /usr).
    
    See: https://github.com/systemd/systemd/issues/18082
    See: https://github.com/systemd/systemd/commit/1c2c7c6cb3d92315624f3711114e86b0acfbce63

 meson.build | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index 97304609..57ed5aac 100644
--- a/meson.build
+++ b/meson.build
@@ -281,12 +281,12 @@ if install_systemd_systemduserunitdir or install_systemd_tmpfilesdir
 
     if install_systemd_systemduserunitdir and systemd_systemduserunitdir == ''
       assert(systemd_dep.found(), 'systemd required but not found, please provide a valid systemd user unit 
dir or disable it')
-      systemd_systemduserunitdir = systemd_dep.get_pkgconfig_variable('systemduserunitdir')
+      systemd_systemduserunitdir = systemd_dep.get_pkgconfig_variable('systemduserunitdir', define_variable: 
['prefix', gvfs_prefix])
     endif
 
     if install_systemd_tmpfilesdir and systemd_tmpfilesdir == ''
       assert(systemd_dep.found(), 'systemd not found, if you use opentmpfiles please provide a valid systemd 
user unit dir or disable it')
-      systemd_tmpfilesdir = systemd_dep.get_pkgconfig_variable('tmpfilesdir')
+      systemd_tmpfilesdir = systemd_dep.get_pkgconfig_variable('tmpfilesdir', define_variable: ['prefix', 
gvfs_prefix])
     endif
   endif
 endif