fix error handling

Author: lieff

src/nanovg.c

@@ -288,7 +288,11 @@ NVGcontext* nvgCreateInternal(NVGparams* params)
 	FONSparams fontParams;
 	NVGcontext* ctx = (NVGcontext*)malloc(sizeof(NVGcontext));
 	int i;
-	if (ctx == NULL) goto error;
+	if (ctx == NULL) {
+		if (ctx->params.userPtr)
+			free(ctx->params.userPtr);
+		goto error;
+	}
 	memset(ctx, 0, sizeof(NVGcontext));
 
 	ctx->params = *params;

src/nanovg_gl.h

@@ -1589,7 +1589,7 @@ NVGcontext* nvgCreateGLES3(int flags)
 	return ctx;
 
 error:
-	if (gl != NULL) free(gl);
+	// 'gl' is freed by nvgDeleteInternal.
 	return NULL;
 }