spaceman: Add table header for -d option

The xfs_spaceman utility did not have a a proper title to the content
displayed using -d (debug) option.

Old output:

$ sudo xfs_spaceman -c "freesp -d" /media/xfs
       0        4        1
       0        5        1
       0        6        1
       0        7        1
.....

This patch adds a suitable title header to the output, making it much
more readable to the user.

New output:

$ sudo xfs_spaceman -c "freesp -d" /media/xfs
    agno    agbno      len
       0        4        1
       0        5        1
       0        6        1
       0        7        1
....

Signed-off-by: Dhruvesh Rathore <dhruvesh_r@outlook.com>
Signed-off-by: Amey Ruikar <ameyruikar@yahoo.com>
Signed-off-by: Somdeep Dey <somdeepdey10@gmail.com>

spaceman/freesp.c

diff --git a/spaceman/freesp.c b/spaceman/freesp.c
index b5b353d..835c504 100644
--- a/spaceman/freesp.c
+++ b/spaceman/freesp.c
@@ -327,6 +327,10 @@
 
 	if (!init(argc, argv))
 		return 0;
+
+	if (dumpflag)
+		printf("%8s %8s %8s\n", "agno", "agbno", "len");
+
 	for (agno = 0; agno < file->geom.agcount; agno++)  {
 		if (inaglist(agno))
 			scan_ag(agno);