Add fflush after program and erase operations

  This is needed to keep the file in sync during swap operations if reset occurs, because the file is closed only at the end of the swap process.

Author: pennam

app/fileblockdevice/FileBlockDevice.cpp

@@ -121,6 +121,12 @@ int FileBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size)
         return BD_ERROR_DEVICE_ERROR;
     }
 
+    err = fflush(_file[0]);
+    if (err != 0u) {
+        printf("E-Program:flush\n");
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
     return BD_ERROR_OK;
 }
 
@@ -148,6 +154,12 @@ int FileBlockDevice::erase(bd_addr_t addr, bd_size_t size)
         }
     }
 
+    int err = fflush(_file[0]);
+    if (err != 0u) {
+        printf("E-Erase:flush\n");
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
     return BD_ERROR_OK;
 }