Remove invalid assert and move uVisor warning to correct function

hal/mbed_critical_section_api.c

@@ -36,27 +36,14 @@ MBED_WEAK void hal_critical_section_enter(void)
 {
     critical_interrupts_enabled = are_interrupts_enabled();
 
-#ifndef FEATURE_UVISOR
-    // If we are in a nested critical section and interrupts are still enabled
-    // something has gone wrong.
-    MBED_ASSERT(!are_interrupts_enabled());
-#else
-    #warning "core_util_critical_section_enter needs fixing to work from unprivileged code"
-#endif /* FEATURE_UVISOR */
-
     __disable_irq();
 }
 
 
 MBED_WEAK void hal_critical_section_exit()
 {
-// FIXME
-#ifndef FEATURE_UVISOR
     // Interrupts must be disabled on invoking an exit from a critical section
     MBED_ASSERT(!are_interrupts_enabled());
-#else
-    #warning "core_util_critical_section_exit needs fixing to work from unprivileged code"
-#endif /* FEATURE_UVISOR */
 
     // Restore the IRQs to their state prior to entering the critical section
     if (critical_interrupts_enabled == true) {

platform/mbed_critical.c

@@ -58,6 +58,11 @@ bool core_util_in_critical_section(void)
 
 void core_util_critical_section_enter(void)
 {
+// FIXME
+#ifdef FEATURE_UVISOR
+    #warning "core_util_critical_section_enter needs fixing to work from unprivileged code"
+#endif /* FEATURE_UVISOR */
+
     // If the reentrancy counter overflows something has gone badly wrong.
     MBED_ASSERT(critical_section_reentrancy_counter < UINT32_MAX);
 
@@ -70,6 +75,11 @@ void core_util_critical_section_enter(void)
 
 void core_util_critical_section_exit(void)
 {
+// FIXME
+#ifdef FEATURE_UVISOR
+    #warning "core_util_critical_section_exit needs fixing to work from unprivileged code"
+#endif /* FEATURE_UVISOR */
+
     // If critical_section_enter has not previously been called, do nothing
     if (critical_section_reentrancy_counter == 0) {
         return;