fbt: fixed linter paths (#1930)

* fbt: fixed linter paths
* lint: changed file permissions

Co-authored-by: あく <alleteam@gmail.com>

furi/SConscript

@@ -1,6 +1,11 @@
 Import("env")
 
-env.Append(LINT_SOURCES=["furi"])
+env.Append(
+    LINT_SOURCES=[
+        "furi",
+        "furi/core",
+    ]
+)
 
 
 libenv = env.Clone(FW_LIB_NAME="furi")

furi/core/timer.c

@@ -86,7 +86,7 @@ void furi_timer_free(FuriTimer* instance) {
 
     furi_check(xTimerDelete(hTimer, portMAX_DELAY) == pdPASS);
 
-    while (furi_timer_is_running(instance)) furi_delay_tick(2);
+    while(furi_timer_is_running(instance)) furi_delay_tick(2);
 
     if((uint32_t)callb & 1U) {
         /* Callback memory was allocated from dynamic pool, clear flag */