Fix code style for key derivation input function

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 63c6ad4..57533cc 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -7489,7 +7489,7 @@
     psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
 
     if (kdf_alg == 0) {
-       /* This is a blank or aborted operation. */
+        /* This is a blank or aborted operation. */
         status = PSA_ERROR_BAD_STATE;
         goto exit;
     }