autogen.sh: fix removal of autom4te.cache

https://bugs.webkit.org/show_bug.cgi?id=121150

Reviewed by Carlos Garcia Campos.

The removal of autom4te.cache is wrong, it uses 'rm -f' instead of
'rm -rf' and it relies on an undefined variable.

In addition to that, it should be done after running autoreconf,
which is when it's no longer needed.

* autogen.sh:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@155517 268f45cc-cd09-0410-ab3c-d52691b4dbfc

ChangeLog

@@ -1,3 +1,18 @@
+2013-09-11  Alberto Garcia  <[email protected]>
+
+        autogen.sh: fix removal of autom4te.cache
+        https://bugs.webkit.org/show_bug.cgi?id=121150
+
+        Reviewed by Carlos Garcia Campos.
+
+        The removal of autom4te.cache is wrong, it uses 'rm -f' instead of
+        'rm -rf' and it relies on an undefined variable.
+
+        In addition to that, it should be done after running autoreconf,
+        which is when it's no longer needed.
+
+        * autogen.sh:
+
 2013-09-11  Alberto Garcia  <[email protected]>
 
         Unquoted $ORIGDIR in autogen.sh

autogen.sh

@@ -8,15 +8,14 @@ test -z "$srcdir" && srcdir=.
 ORIGDIR=`pwd`
 cd "$srcdir" || exit 1
 
-rm -f $top_srcdir/autom4te.cache
-
 touch README INSTALL
 
 if test -z `which autoreconf`; then
     echo "Error: autoreconf not found, please install it."
     exit 1
 fi
 autoreconf --verbose --install -I Source/autotools $ACLOCAL_FLAGS|| exit $?
+rm -rf autom4te.cache
 
 cd "$ORIGDIR" || exit 1