cppcheck: (error) Uninitialized variable

Resolve the following uninitialized variable warnings.  In practice
these were unreachable due to the goto.  Replacing the goto with a
return resolves the warning and yields more readable code.

[module/icp/algs/modes/ccm.c:892]: (error) Uninitialized variable: ccm_param
[module/icp/algs/modes/ccm.c:893]: (error) Uninitialized variable: ccm_param
[module/icp/algs/modes/gcm.c:564]: (error) Uninitialized variable: gcm_param
[module/icp/algs/modes/gcm.c:565]: (error) Uninitialized variable: gcm_param
[module/icp/algs/modes/gcm.c:599]: (error) Uninitialized variable: gmac_param
[module/icp/algs/modes/gcm.c:600]: (error) Uninitialized variable: gmac_param

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes openzfs#9732

module/icp/algs/modes/ccm.c

@@ -885,15 +885,13 @@ ccm_init_ctx(ccm_ctx_t *ccm_ctx, char *param, int kmflag,
 
 		ccm_ctx->ccm_flags |= CCM_MODE;
 	} else {
-		rv = CRYPTO_MECHANISM_PARAM_INVALID;
-		goto out;
+		return (CRYPTO_MECHANISM_PARAM_INVALID);
 	}
 
 	if (ccm_init(ccm_ctx, ccm_param->nonce, ccm_param->ulNonceSize,
 	    ccm_param->authData, ccm_param->ulAuthDataSize, block_size,
 	    encrypt_block, xor_block) != 0) {
-		rv = CRYPTO_MECHANISM_PARAM_INVALID;
-		goto out;
+		return (CRYPTO_MECHANISM_PARAM_INVALID);
 	}
 	if (!is_encrypt_init) {
 		/* allocate buffer for storing decrypted plaintext */
@@ -903,7 +901,6 @@ ccm_init_ctx(ccm_ctx_t *ccm_ctx, char *param, int kmflag,
 			rv = CRYPTO_HOST_MEMORY;
 		}
 	}
-out:
 	return (rv);
 }
 

module/icp/algs/modes/gcm.c

@@ -553,16 +553,15 @@ gcm_init_ctx(gcm_ctx_t *gcm_ctx, char *param, size_t block_size,
 		rv = CRYPTO_SUCCESS;
 		gcm_ctx->gcm_flags |= GCM_MODE;
 	} else {
-		rv = CRYPTO_MECHANISM_PARAM_INVALID;
-		goto out;
+		return (CRYPTO_MECHANISM_PARAM_INVALID);
 	}
 
 	if (gcm_init(gcm_ctx, gcm_param->pIv, gcm_param->ulIvLen,
 	    gcm_param->pAAD, gcm_param->ulAADLen, block_size,
 	    encrypt_block, copy_block, xor_block) != 0) {
 		rv = CRYPTO_MECHANISM_PARAM_INVALID;
 	}
-out:
+
 	return (rv);
 }
 
@@ -588,16 +587,15 @@ gmac_init_ctx(gcm_ctx_t *gcm_ctx, char *param, size_t block_size,
 		rv = CRYPTO_SUCCESS;
 		gcm_ctx->gcm_flags |= GMAC_MODE;
 	} else {
-		rv = CRYPTO_MECHANISM_PARAM_INVALID;
-		goto out;
+		return (CRYPTO_MECHANISM_PARAM_INVALID);
 	}
 
 	if (gcm_init(gcm_ctx, gmac_param->pIv, AES_GMAC_IV_LEN,
 	    gmac_param->pAAD, gmac_param->ulAADLen, block_size,
 	    encrypt_block, copy_block, xor_block) != 0) {
 		rv = CRYPTO_MECHANISM_PARAM_INVALID;
 	}
-out:
+
 	return (rv);
 }