cmd/blk_common: clarify no partition error message

When no partition table is found, users should be warned so.
Warning that no device is available in this case could be misleading,
especially as it is the same error when no device is selected.

Signed-off-by: Alexandre Besnard <alexandre.besnard@softathome.com>

cmd/blk_common.c

@@ -32,7 +32,8 @@ int blk_common_cmd(int argc, char * const argv[], enum if_type if_type,
 			return 0;
 		} else if (strncmp(argv[1], "part", 4) == 0) {
 			if (blk_list_part(if_type))
-				printf("\nno %s devices available\n", if_name);
+				printf("\nno %s partition table available\n",
+				       if_name);
 			return 0;
 		}
 		return CMD_RET_USAGE;