Wrap the source code at 80 characters.
Align the backslashes in "ext2_config_help".
Tested with:
$ nbdkit null --filter=ext2 --help
 [...]
 ext2file=<FILENAME>  (required) Absolute name of file to serve inside
                      the disk image, or 'exportname' for client choice.
 [...] 
Bugzilla: 
https://bugzilla.redhat.com/show_bug.cgi?id=2172516
Signed-off-by: Laszlo Ersek <lersek(a)redhat.com>
---
 filters/ext2/ext2.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/filters/ext2/ext2.c b/filters/ext2/ext2.c
index f9858ca40d15..cff5dad789d8 100644
--- a/filters/ext2/ext2.c
+++ b/filters/ext2/ext2.c
@@ -96,9 +96,9 @@ ext2_config_complete (nbdkit_next_config_complete *next, nbdkit_backend
*nxdata)
   return next (nxdata);
 }
 
-#define ext2_config_help \
-  "ext2file=<FILENAME>  (required) Absolute name of file to serve inside
the\n" \
-  "                     disk image, or 'exportname' for client
choice."
+#define ext2_config_help                                                    \
+  "ext2file=<FILENAME>  (required) Absolute name of file to serve
inside\n" \
+  "                     the disk image, or 'exportname' for client
choice."
 
 /* The per-connection handle. */
 struct handle {