Correct reserved blocks to segments

Align units to a segment unit when adjusting free segment number.

Test: run the smart idle maint service.
Change-Id: I4fd74ac92adc4ae1a0ded4a7df75a690d829eb20
Signed-off-by: Daeho Jeong <daehojeong@google.com>
diff --git a/IdleMaint.cpp b/IdleMaint.cpp
index 1a6c0a6..7d3eaf4 100644
--- a/IdleMaint.cpp
+++ b/IdleMaint.cpp
@@ -551,9 +551,9 @@
 
     int32_t freeSegments = std::stoi(freeSegmentsStr);
     int32_t dirtySegments = std::stoi(dirtySegmentsStr);
-    int32_t reservedBlocks = std::stoi(ovpSegmentsStr) + std::stoi(reservedBlocksStr);
+    int32_t reservedSegments = std::stoi(ovpSegmentsStr) + std::stoi(reservedBlocksStr) / 512;
 
-    freeSegments = freeSegments > reservedBlocks ? freeSegments - reservedBlocks : 0;
+    freeSegments = freeSegments > reservedSegments ? freeSegments - reservedSegments : 0;
     int32_t totalSegments = freeSegments + dirtySegments;
     int32_t finalTargetSegments = 0;