Remove redundant SIZE_MAX guards

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index 13fa6d4..acc4208 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -98,14 +98,13 @@
     if (len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT) {
         return MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG;
     }
-#if SIZE_MAX > INT_MAX
+
     /* This shouldn't be an issue because
      * MBEDTLS_CTR_DRBG_MAX_SEED_INPUT < INT_MAX in any sensible
      * configuration, but make sure anyway. */
     if (len > INT_MAX) {
         return MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG;
     }
-#endif
 
     /* For backward compatibility with Mbed TLS <= 2.19, store the
      * entropy nonce length in a field that already exists, but isn't