[PATCH] uml: revert compile-time option checking

Undo the previous no-modes patch since Adrian Bunk sent in a kbuild way of
doing the same thing.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/kernel/um_arch.c

@@ -243,10 +243,6 @@ static int __init mode_tt_setup(char *line, int *add)
 	return(0);
 }
 
-#else
-
-#error Either CONFIG_MODE_TT or CONFIG_MODE_SKAS must be enabled
-
 #endif
 #endif
 #endif