build: Fix autogen.sh $LIBTOOLIZE detection logic

* Don't silence `libtoolize --version` error message. It would be
useful for diagnosing any problem when `libtoolize --version` fails.
(libtoolize not found? No permission to execute? Now you know which
error it is.)
* Change the guessing code of libtoolize program name to a loop.
It'll perform silently.
* Silence the `libtoolize --version` output when it succeeds.

Signed-off-by: Kang-che Sung <[email protected]>

Author: Explorer09

autogen.sh

@@ -25,19 +25,20 @@
 # and procede with the "normal" build procedures.
 
 # use LIBTOOLIZE, if set
-LIBTOOLIZE_ORIG="$LIBTOOLIZE";
-if test "x$LIBTOOLIZE" = "x"; then LIBTOOLIZE=libtoolize; fi
+if test "x$LIBTOOLIZE" = "x"; then
+   for ac_prog in libtoolize glibtoolize; do
+      if $ac_prog --version >/dev/null 2>&1; then
+         LIBTOOLIZE=$ac_prog
+         break
+      fi
+   done
+fi
 
 # test libtoolize
-$LIBTOOLIZE --version 2>/dev/null
-if test "$?" -ne 0; then
-   LIBTOOLIZE=glibtoolize
-   $LIBTOOLIZE --version 2>/dev/null
-   if test "$?" -ne 0; then
-      echo "error: libtoolize not working, re-run with LIBTOOLIZE=/path/to/libtoolize">&2
-      echo "       LIBTOOLIZE is currently \"$LIBTOOLIZE_ORIG\"">&2
-      exit 1
-   fi
+if test "x$LIBTOOLIZE" = "x" || ! $LIBTOOLIZE --version >/dev/null; then
+   echo "error: libtoolize not working, re-run with LIBTOOLIZE=/path/to/libtoolize">&2
+   echo "       LIBTOOLIZE is currently \"$LIBTOOLIZE\"">&2
+   exit 1
 fi
 
 #if we pretend to have a ChangeLog, then automake is less