bitbake: toaster: exit or return depending on the mode

When toaster script is sourced 'return' should be used as
using 'exit' will cause script to exit the shell and close terminal
window. If script is called 'exit' should be used. Otherwise shell
will throw and error:
  return: can only `return' from a function or sourced script

Used 'return' or 'exit' depending on the toaster mode using
TOASTER_MANAGED variable.

(Bitbake rev: 643c42069a2788e9f40fa1bc9845f32aed3d096c)

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

bitbake/bin/toaster

@@ -201,7 +201,7 @@ if [ "$TOASTER_CONF" = "" ]; then
 fi
 if [ ! -f $TOASTER_CONF ]; then
     echo "$TOASTER_CONF configuration file not found. set TOASTER_CONF to specify a path"
-    exit 1;
+    [ "$TOASTER_MANAGED" = '1' ] && exit 1 || return 1
 fi
 # this defines the dir toaster will use for
 # 1) clones of layers (in _toaster_clones )