lib/zlib: drop EQUAL macro

The macro is prehistoric, and only exists to help those readers who don't
know what memcmp() returns if memory areas differ.  This is pretty well
documented, so the macro looks excessive.

Now that the only user of the macro depends on DEBUG_ZLIB config, GCC
warns about unused macro if the library is built with W=2 against
defconfig.  So drop it for good.

Link: https://lkml.kernel.org/r/20250205212933.68695-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Heiko Carsten <heiko.carstens@de.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/zlib_deflate/deflate.c b/lib/zlib_deflate/deflate.c
index 3a1d8d34182e4f8812369aa662e1d9f2c3532f1f..8fb2a3e17c0e338d933506410ef4604a57bb9b24 100644 (file)
--- a/lib/zlib_deflate/deflate.c
+++ b/lib/zlib_deflate/deflate.c
@@ -151,9 +151,6 @@ static const config configuration_table[10] = {
  * meaning.
  */
 
-#define EQUAL 0
-/* result of memcmp for equal strings */
-
 /* ===========================================================================
  * Update a hash value with the given input byte
  * IN  assertion: all calls to UPDATE_HASH are made with consecutive
@@ -713,8 +710,7 @@ static void check_match(
 )
 {
     /* check that the match is indeed a match */
-    if (memcmp((char *)s->window + match,
-                (char *)s->window + start, length) != EQUAL) {
+    if (memcmp((char *)s->window + match, (char *)s->window + start, length)) {
         fprintf(stderr, " start %u, match %u, length %d\n",
                start, match, length);
         do {