squisher: force hardlink.

Change-Id: I5741918615d101d2553fb7cdd02b0c5242970bc9
diff --git a/tools/squisher b/tools/squisher
index 70fedda..a3f8a45 100755
--- a/tools/squisher
+++ b/tools/squisher
@@ -35,7 +35,7 @@
 echo -e $CL_CYN"MODVERSION: $MODVERSION"$CL_RST
 OUTFILE=$OUT/cm-$MODVERSION.zip
 
-ln $OTAPACKAGE $OUTFILE
+ln -f $OTAPACKAGE $OUTFILE
 
 # Create a md5 checksum image of the repacked package
 (