Remove _() and N_() from platform.h. #define them as NOP macros in the two

files still using them.  I didn't remove them from e2fsck.c to avoid stomping
pending cleanup patches from Garrett, and I didn't bother to remove them from
fdisk.c because that entire file needs to be rewritten from scratch.

util-linux/fdisk.c

@@ -10,6 +10,8 @@
 #define UTIL_LINUX_VERSION "2.12"
 
 
+#define _(x) x
+
 #define PROC_PARTITIONS "/proc/partitions"
 
 #include <features.h>