test: Update comment for fs_helper.setup_image()

This function actually allows creating two partitions now, so update its
comment to match that.

Signed-off-by: Simon Glass <simon.glass@canonical.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

test/py/tests/fs_helper.py

@@ -85,7 +85,7 @@ def mk_fs(config, fs_type, size, prefix, src_dir=None, size_gran = 0x100000,
 
 def setup_image(ubman, devnum, part_type, img_size=20, second_part=False,
                 basename='mmc'):
-    """Create a disk image with a single partition
+    """Create a disk image with one or two partitions
 
     Args:
         ubman (ConsoleBase): Console to use