blkid: update man page/usage()

The "-s <tag>" options is usable for low-level probing more too. This
feature should be documented.

Signed-off-by: Karel Zak <kzak@redhat.com>

misc-utils/blkid.8

@@ -33,6 +33,8 @@ blkid \- command\-line utility to locate/print block device attributes
 
 .B blkid
 .RB -p
+.RB [ \-s
+.IR tag ]
 .RB [ \-O
 .IR offset ]
 .RB [ \-S

misc-utils/blkid.c

@@ -57,7 +57,8 @@ static void usage(int error)
 		"  %1$s -L <label> | -U <uuid>\n\n"
 		"  %1$s [-c <file>] [-ghlLv] [-o format] [-s <tag>] \n"
 		"        [-t <token>] [-w <file>] [dev ...]\n\n"
-		"  %1$s -p [-O <offset>] [-S <size>] [-o format] <dev> [dev ...]\n\n"
+		"  %1$s -p [-s <tag>] [-O <offset>] [-S <size>] \n"
+		"        [-o format] <dev> [dev ...]\n\n"
 		"Options:\n"
 		"  -c <file>   cache file (default: /etc/blkid.tab, /dev/null = none)\n"
 		"  -h          print this usage message and exit\n"