[PATCH] uml: hostfs failed mount handling

This cleans up the error handling and fixes a crash if a hostfs mount fails.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>