[gparted] Tidy up Autoconf check for --enable-libparted-dmraid (#734076)

[Curtis Gedak <gedakc src gnome org>]

commit 5c73f3de5722a192e06c5ae0fc6c92e7ba752c7e
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Tue Aug 12 12:11:58 2014 +0100

    Tidy up Autoconf check for --enable-libparted-dmraid (#734076)
    
    Use AC_ARG_ENABLE() Autoconf macro to set enable_libparted_dmraid
    variable to either yes or no in all cases, whether set on the command
    line or not.  Use AS_HELP_STRING() macro to format the option help text.
    
    Bug #734076 - Autodetect parted online partition resizing capability

 configure.ac |   21 ++++++++++++---------
 1 files changed, 12 insertions(+), 9 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 5790380..5a97053 100644
--- a/configure.ac
+++ b/configure.ac
@@ -264,17 +264,20 @@ AM_CONDITIONAL([DISABLE_DOC], [test ${enable_doc} = no])
 dnl======================
 dnl check whether to use native libparted dmraid support
 dnl======================
-AC_ARG_ENABLE([libparted_dmraid],
-  [  --enable-libparted-dmraid   do use native libparted /dev/mapper dmraid support],,)
-if test "x${enable_libparted_dmraid}" = "x" ; then
-       enable_libparted_dmraid=no
-fi
+AC_ARG_ENABLE(
+       [libparted_dmraid],
+       AS_HELP_STRING(
+               [--enable-libparted-dmraid],
+               [use native libparted /dev/mapper dmraid support @<:@default=disabled@:>@]),
+       [enable_libparted_dmraid=$enableval],
+       [enable_libparted_dmraid=no]
+)
 
-AC_MSG_CHECKING([whether native libparted /dev/mapper dmraid support should be used])
-if test ${enable_libparted_dmraid} = yes; then
+AC_MSG_CHECKING([whether to use native libparted /dev/mapper dmraid support])
+if test "x$enable_libparted_dmraid" = xyes; then
+       AC_DEFINE([USE_LIBPARTED_DMRAID], [1],
+                 [Define to 1 to use native libparted /dev/mapper dmraid support])
        AC_MSG_RESULT([yes])
-       dnl Set   #define USE_LIBPARTED_DMRAID 1   to indicate documentation not wanted
-       AC_DEFINE([USE_LIBPARTED_DMRAID], [1], [Define to 1 if --enable-libparted-dmraid specified])
 else
        AC_MSG_RESULT([no])
 fi