docs: f2fs: fix a broken table

Commit ed318a6c ("fscrypt: support test_dummy_encryption=v2") added an
entry to the massive option table in Documentation/filesystems/f2fs.txt.
The option was too wide for the formatting of the table, though, leading to
a verbose and ugly warning starting with:

    Documentation/filesystems/f2fs.rst:229: WARNING: Malformed table.
    Text in column margin in table line 126.

Fixing this requires formatting the whole table; let's hear it for Emacs
query-replace-regexp.

Fixes: ed318a6c ("fscrypt: support test_dummy_encryption=v2")
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/filesystems/f2fs.rst

@@ -101,7 +101,7 @@ Mount Options
 =============
 
 
-====================== ============================================================
+======================== ============================================================
 background_gc=%s	 Turn on/off cleaning operations, namely garbage
 			 collection, triggered in background when I/O subsystem is
 			 idle. If background_gc=on, it will turn on the garbage
@@ -258,7 +258,7 @@ compress_extension=%s  Support adding specified extension, so that f2fs can enab
 			 on compression extension list and enable compression on
 			 these file by default rather than to enable it via ioctl.
 			 For other files, we can still enable compression via ioctl.
-====================== ============================================================
+======================== ============================================================
 
 Debugfs Entries
 ===============