patch 8.2.3529: xxd usage output is incomplete

Problem:    Xxd usage output is incomplete.
Solution:   Add "bytes" to "-g" flag. (Atsushi Sugawara, closes #8944)
diff --git a/src/version.c b/src/version.c
index b1fc4dc..77eb6e1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3529,
+/**/
     3528,
 /**/
     3527,
diff --git a/src/xxd/xxd.c b/src/xxd/xxd.c
index 698971a..4e35203 100644
--- a/src/xxd/xxd.c
+++ b/src/xxd/xxd.c
@@ -224,7 +224,7 @@
   fprintf(stderr, "    -c cols     format <cols> octets per line. Default 16 (-i: 12, -ps: 30).\n");
   fprintf(stderr, "    -E          show characters in EBCDIC. Default ASCII.\n");
   fprintf(stderr, "    -e          little-endian dump (incompatible with -ps,-i,-r).\n");
-  fprintf(stderr, "    -g          number of octets per group in normal output. Default 2 (-e: 4).\n");
+  fprintf(stderr, "    -g bytes    number of octets per group in normal output. Default 2 (-e: 4).\n");
   fprintf(stderr, "    -h          print this summary.\n");
   fprintf(stderr, "    -i          output in C include file style.\n");
   fprintf(stderr, "    -l len      stop after <len> octets.\n");