Fix regression in directory scanning

Previous range-checking fix removed an inequality check. This change
restores it.

Offending change was I5eb310ced58c3c64a7af2d11b80326efe5adbcab

Change-Id: Ic952c3ba5a4f7e5ab2148ec623b6f083cb7495fb
diff --git a/media/libmedia/MediaScanner.cpp b/media/libmedia/MediaScanner.cpp
index 43762e7..843a8fd 100644
--- a/media/libmedia/MediaScanner.cpp
+++ b/media/libmedia/MediaScanner.cpp
@@ -58,7 +58,7 @@
 
     int pathRemaining = PATH_MAX - pathLength;
     strcpy(pathBuffer, path);
-    if (pathLength > 0 && pathBuffer[pathLength - 1]) {
+    if (pathLength > 0 && pathBuffer[pathLength - 1] != '/') {
         pathBuffer[pathLength] = '/';
         pathBuffer[pathLength + 1] = 0;
         --pathRemaining;