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/shared/mount-util.c

@@ -45,7 +45,7 @@ int umount_recursive_full(const char *prefix, int flags, char **keep) {
 
         f = fopen("/proc/self/mountinfo", "re"); /* Pin the file, in case we unmount /proc/ as part of the logic here */
         if (!f)
-                return log_debug_errno(errno, "Failed to open /proc/self/mountinfo: %m");
+                return log_debug_errno(errno, "Failed to open %s: %m", "/proc/self/mountinfo");
 
         for (;;) {
                 _cleanup_(mnt_free_tablep) struct libmnt_table *table = NULL;
@@ -454,7 +454,7 @@ int bind_remount_one(const char *path, unsigned long new_flags, unsigned long fl
 
         proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
         if (!proc_self_mountinfo)
-                return log_debug_errno(errno, "Failed to open /proc/self/mountinfo: %m");
+                return log_debug_errno(errno, "Failed to open %s: %m", "/proc/self/mountinfo");
 
         return bind_remount_one_with_mountinfo(path, new_flags, flags_mask, proc_self_mountinfo);
 }