wic: move WicError to lib/wic/__init__.py

Removed unused exceptions from error.py
Moved definition of WicError to lib/wic/__init__.py

(From OE-Core rev: 15442d072bb6d93bd9b941726f93262503053da5)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/wic/utils/misc.py

@@ -33,7 +33,7 @@ import re
 from collections import defaultdict
 from distutils import spawn
 
-from wic.errors import WicError
+from wic import WicError
 from wic.utils import runner
 
 logger = logging.getLogger('wic')

scripts/lib/wic/utils/runner.py

@@ -19,7 +19,7 @@ import logging
 import os
 import subprocess
 
-from wic.errors import WicError
+from wic import WicError
 
 logger = logging.getLogger('wic')