partitions/aix: append null character to print data from disk

BugLink: https://bugs.launchpad.net/bugs/1787281

Even if properly initialized, the lvname array (i.e., strings)
is read from disk, and might contain corrupt data (e.g., lack
the null terminating character for strings).

So, make sure the partition name string used in pr_warn() has
the null terminating character.

Fixes: 6ceea22 ("partitions: add aix lvm partition support files")
Suggested-by: Daniel J. Axtens <daniel.axtens@canonical.com>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit d43fdae7bac2def8c4314b5a49822cb7f08a45f1)
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

Author: Mauricio Faria de Oliveira

block/partitions/aix.c

@@ -282,10 +282,14 @@ int aix_partition(struct parsed_partitions *state)
 				next_lp_ix += 1;
 		}
 		for (i = 0; i < state->limit; i += 1)
-			if (lvip[i].pps_found && !lvip[i].lv_is_contiguous)
+			if (lvip[i].pps_found && !lvip[i].lv_is_contiguous) {
+				char tmp[sizeof(n[i].name) + 1]; // null char
+
+				snprintf(tmp, sizeof(tmp), "%s", n[i].name);
 				pr_warn("partition %s (%u pp's found) is "
 					"not contiguous\n",
-					n[i].name, lvip[i].pps_found);
+					tmp, lvip[i].pps_found);
+			}
 		kfree(pvd);
 	}
 	kfree(n);