Fix R_CreateImage() crash with r_logFile

Fixes a crash resulting from `va()` overflow.

Author: VReaperV

src/engine/renderer/tr_image.cpp

@@ -3101,9 +3101,10 @@ qhandle_t RE_GenerateTexture( const byte *pic, int width, int height )
 		return 0;
 	}
 
-	const char *name = va( "rocket%d", numTextures++ );
 	R_SyncRenderThread();
 
+	const char *name = va( "rocket%d", numTextures++ );
+
 	imageParams_t imageParams = {};
 	imageParams.bits = IF_NOPICMIP;
 	imageParams.filterType = filterType_t::FT_LINEAR;