Unify function parameters

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/constant_time_internal.h b/library/constant_time_internal.h
index 90d1ac6..a13e7b2 100644
--- a/library/constant_time_internal.h
+++ b/library/constant_time_internal.h
@@ -169,7 +169,7 @@
 
 #if defined(MBEDTLS_BASE64_C)
 
-unsigned char mbedtls_ct_base64_enc_char( unsigned char val );
+unsigned char mbedtls_ct_base64_enc_char( unsigned char value );
 
 signed char mbedtls_ct_base64_dec_value( unsigned char c );