get rid of read to str

src/sys.cpp

@@ -28,9 +28,10 @@ void sys::getTimeDate(TimeDate* td) {
 }
 
 void sys::getRam(Memory* mem) {
-    auto content = readFileToStr("/proc/meminfo", 128);  // file is longer than that but its all we need
-    mem->free = getVal("MemAvailable:", content);
-    mem->total = getVal("MemTotal:", content);
+    static char buf[128]; // file is longer but we only need first 128 chars
+    readFile("/proc/meminfo", buf, sizeof(buf));
+    mem->free = getVal("MemAvailable:", std::string_view(buf));
+    mem->total = getVal("MemTotal:", std::string_view(buf));
     mem->used = mem->total - mem->free;
 }