various: do not include file names directly in error messages

git grep -l 'Failed to open /'|xargs sed -r -i 's|"Failed to open (/[^ ]+): %m"|"Failed to open %s: %m", "\1"|g'
git grep -l $'Failed to open \'/'|xargs sed -r -i $'s|"Failed to open \'(/[^ ]+)\': %m"|"Failed to open %s: %m", "\\1"|g'
git grep -l "Failed to open /"|xargs sed -r -i $'s|"Failed to open (/[^ ]+), ignoring: %m"|"Failed to open %s, ignoring: %m", "\\1"|g'
+ some manual fixups.

src/journal/bsod.c

@@ -156,7 +156,7 @@ static int display_emergency_message_fullscreen(const char *message) {
         else {
                 fd = open_terminal("/dev/tty1", O_RDWR|O_NOCTTY|O_CLOEXEC);
                 if (fd < 0)
-                        return log_error_errno(fd, "Failed to open /dev/tty1: %m");
+                        return log_error_errno(fd, "Failed to open %s: %m", "/dev/tty1");
 
                 r = find_next_free_vt(fd, &free_vt, &original_vt);
                 if (r < 0)

src/journal/journald-manager.c

@@ -2059,7 +2059,7 @@ static int manager_open_hostname(Manager *m) {
         m->hostname_fd = open("/proc/sys/kernel/hostname",
                               O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
         if (m->hostname_fd < 0)
-                return log_error_errno(errno, "Failed to open /proc/sys/kernel/hostname: %m");
+                return log_error_errno(errno, "Failed to open %s: %m", "/proc/sys/kernel/hostname");
 
         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, dispatch_hostname_change, m);
         if (r < 0)