Fixing onos-build-selective to warp into the $ONOS_ROOT directory as a first thing.

Change-Id: Ic953978f1b6add6909bde2fef2fddd8471f97bf3
diff --git a/tools/dev/bin/onos-build-selective b/tools/dev/bin/onos-build-selective
index 35ad72e..ac2dec8 100755
--- a/tools/dev/bin/onos-build-selective
+++ b/tools/dev/bin/onos-build-selective
@@ -3,6 +3,8 @@
 # Selectively builds only those projects that contained modified Java files.
 # ----------------------------------------------------------------------------
 
+cd $ONOS_ROOT
+
 projects=$(find $ONOS_ROOT -type f -path '*/src/*' \
     -exec $ONOS_ROOT/tools/dev/bin/onos-build-selective-hook {} \; | \
         grep -v -f $ONOS_ROOT/tools/dev/bin/onos-build-selective.exclude | \