imsm: block using partition

When IMSM_NO_PLATFORM is exported mdadm allows to create array with
partitions or add partition to existing array but there is no
possibilty to assemble it after stopping, see commit 691c6ee
("IMSM/DDF: don't recognised these metadata on partitions.").

When searching for hba capabilities first test device and print
corresponding error if it is a partition.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

super-intel.c

@@ -4523,6 +4523,11 @@ static int find_intel_hba_capability(int fd, struct intel_super *super, char *de
 	struct sys_dev *hba_name;
 	int rv = 0;
 
+	if (fd >= 0 && test_partition(fd)) {
+		pr_err("imsm: %s is a partition, cannot be used in IMSM\n",
+		       devname);
+		return 1;
+	}
 	if (fd < 0 || check_env("IMSM_NO_PLATFORM")) {
 		super->orom = NULL;
 		super->hba = NULL;