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/udev/udev-builtin-btrfs.c

@@ -43,7 +43,7 @@ static int builtin_btrfs(UdevEvent *event, int argc, char *argv[]) {
                         return 0;
                 }
 
-                return log_device_debug_errno(dev, errno, "Failed to open /dev/btrfs-control: %m");
+                return log_device_debug_errno(dev, errno, "Failed to open %s: %m", "/dev/btrfs-control");
         }
 
         struct btrfs_ioctl_vol_args args = {};

src/udev/udev-watch.c

@@ -415,7 +415,7 @@ static int udev_watch_clear_by_wd(sd_device *dev, int dirfd, int wd) {
         if (dirfd < 0) {
                 dirfd_close = RET_NERRNO(open("/run/udev/watch/", O_CLOEXEC | O_DIRECTORY | O_NOFOLLOW | O_RDONLY));
                 if (dirfd_close < 0)
-                        return log_device_debug_errno(dev, dirfd_close, "Failed to open '/run/udev/watch/': %m");
+                        return log_device_debug_errno(dev, dirfd_close, "Failed to open %s: %m", "/run/udev/watch/");
 
                 dirfd = dirfd_close;
         }
@@ -595,7 +595,7 @@ int manager_remove_watch(Manager *manager, sd_device *dev) {
         if (dirfd == -ENOENT)
                 return 0;
         if (dirfd < 0)
-                return log_device_debug_errno(dev, dirfd, "Failed to open '/run/udev/watch/': %m");
+                return log_device_debug_errno(dev, dirfd, "Failed to open %s: %m", "/run/udev/watch/");
 
         /* First, clear symlinks. */
         r = udev_watch_clear(dev, dirfd, &wd);