wic/engine.py: Load paths from PATH environment variable

Load self.paths from environment variable and
if it fails, fall back to hardcoded list.
This is required for users that would need to load
different e2fsprogs binaries if their system's ones
are not recent enought

(From OE-Core rev: a88bcbae850a2e6d182291d3f8e167aabdbe4842)

Signed-off-by: William Bourque <wbourque@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/wic/engine.py

@@ -244,8 +244,13 @@ class Disk:
         self._psector_size = None
         self._ptable_format = None
 
-        # find parted
-        self.paths = "/bin:/usr/bin:/usr/sbin:/sbin/"
+        # read paths from $PATH environment variable
+        # if it fails, use hardcoded paths
+        try:
+            self.paths = os.environ['PATH']
+        except KeyError:
+            self.paths = "/bin:/usr/bin:/usr/sbin:/sbin/"
+
         if native_sysroot:
             for path in self.paths.split(':'):
                 self.paths = "%s%s:%s" % (native_sysroot, path, self.paths)