Simplify API key setting for llama_stack

Deduplicate the API key Sprintf call by hoisting the field
name (api_key vs api_token) into a variable and performing
a single assignment after the provider-type branch.

Author: lpiwowar

internal/controller/llama_stack_config.go

@@ -128,18 +128,16 @@ func buildLlamaStackInferenceProviders(_ *common_helper.Helper, _ context.Contex
 			// Determine the appropriate Llama Stack provider type:
 			//  - OpenAI uses remote::openai
 			//  - vLLM uses remote::vllm
+			var apiKeyField string
 			if provider.Type == "openai" {
 				providerConfig["provider_type"] = "remote::openai"
-				// Set API key from environment variable
-				// Llama Stack will substitute ${env.VAR_NAME} with the actual env var value
-				config["api_key"] = fmt.Sprintf("${env.%s%s}", envVarName, EnvVarSuffixAPIKey)
-
+				apiKeyField = "api_key"
 			} else {
 				providerConfig["provider_type"] = "remote::vllm"
-				// Set API token from environment variable for vLLM
-				// Llama Stack will substitute ${env.VAR_NAME} with the actual env var value
-				config["api_token"] = fmt.Sprintf("${env.%s%s}", envVarName, EnvVarSuffixAPIKey)
+				apiKeyField = "api_token"
 			}
+			// Llama Stack will substitute ${env.VAR_NAME} with the actual env var value
+			config[apiKeyField] = fmt.Sprintf("${env.%s%s}", envVarName, EnvVarSuffixAPIKey)
 
 			// Add custom URL if specified
 			if provider.URL != "" {