dm: part: fix missing driver name in debug print

Fixes the following warning with PART_DEBUG enabled:
disk/part.c: In function ‘get_partition_info’:
disk/part.c:372:3: warning: format ‘%s’ expects a matching ‘char *’ argument [-Wformat]

Signed-off-by: Nishanth Menon <nm@ti.com>
diff --git a/disk/part.c b/disk/part.c
index 0aff954..543cab8 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -365,7 +365,8 @@
 		return -EPROTONOSUPPORT;
 	}
 	if (!drv->get_info) {
-		PRINTF("## Driver %s does not have the get_info() method\n");
+		PRINTF("## Driver %s does not have the get_info() method\n",
+		       drv->name);
 		return -ENOSYS;
 	}
 	if (drv->get_info(dev_desc, part, info) == 0) {