ctype: constify read-only _ctype string

While at it, use tabs to indent the comments.
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/ctype.h

@@ -15,7 +15,7 @@
 #define _X	0x40	/* hex digit */
 #define _SP	0x80	/* hard space (0x20) */
 
-extern unsigned char _ctype[];
+extern const unsigned char _ctype[];
 
 #define __ismask(x) (_ctype[(int)(unsigned char)(x)])
 

lib/ctype.c

@@ -7,7 +7,7 @@
 #include <linux/ctype.h>
 #include <linux/module.h>
 
-unsigned char _ctype[] = {
+const unsigned char _ctype[] = {
 _C,_C,_C,_C,_C,_C,_C,_C,				/* 0-7 */
 _C,_C|_S,_C|_S,_C|_S,_C|_S,_C|_S,_C,_C,			/* 8-15 */
 _C,_C,_C,_C,_C,_C,_C,_C,				/* 16-23 */