configure: Fix srcpath when you run configure in the top-level dir

Using the absolute path to configure, otherwise you get:

  [user@locahost qt5]$ ./configure -minimal
  + cd qtbase
  + ./qtbase/configure -minimal
  ./configure: line 58: ./qtbase/configure: No such file or directory

Change-Id: Ic7568cc571aaa52c56bcd28fa1b6bde8abb32c8e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

configure

@@ -41,6 +41,7 @@
 #############################################################################
 
 srcpath=`dirname $0`
+srcpath=`(cd "$srcpath"; /bin/pwd)`
 configure=$srcpath/qtbase/configure
 if [ ! -e "$configure" ]; then
     echo "$configure not found. Did you forget to run \"init-repository\"?" >&2