The kernel's string library does in fact have strcasecmp, at least
since 
ded220bd8f08 ("[STRING]: Move strcasecmp/strncasecmp to
lib/string.c"). Moreover, this open-coded version is in fact wrong: If
the strings only differ in their last character, a and b have already
been incremented to point to the terminating NUL bytes, so they would
wrongly be treated as equal.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
 #include <linux/ptrace.h>
 #include <linux/slab.h>
 #include <linux/string.h>
-#include <linux/ctype.h>
 #include <linux/timer.h>
 #include <asm/byteorder.h>
 #include <asm/io.h>
                domain[REGDOMAINSZ] = 0;
                rc = -EINVAL;
                for (i = 0; i < ARRAY_SIZE(channel_table); i++) {
-                       /* strcasecmp doesn't exist in the library */
-                       char *a = channel_table[i].name;
-                       char *b = domain;
-                       while (*a) {
-                               char c1 = *a++;
-                               char c2 = *b++;
-                               if (tolower(c1) != tolower(c2))
-                                       break;
-                       }
-                       if (!*a && !*b) {
+                       if (!strcasecmp(channel_table[i].name, domain)) {
                                priv->config_reg_domain = channel_table[i].reg_domain;
                                rc = 0;
                        }