build,qt: Drop broken check for -fPIC

* m4/qt6.m4: Remove attempt to build a Qt program with -fPIC.
--

libtool already takes care of adding -fPIC. Moreover, building without
-fPIC succeeded even if Qt was built with -fPIC, i.e. the check didn't
work as intended.

GnuPG-bug-id: 6696

m4/qt6.m4

@@ -41,11 +41,10 @@ AC_DEFUN([FIND_QT6],
     OLDCPPFLAGS=$CPPFLAGS
     OLDLIBS=$LIBS
 
-    # try building without -fPIC
     CPPFLAGS=$GPGME_QT6_CFLAGS
     LIBS=$GPGME_QT6_LIBS
     AC_LANG_PUSH(C++)
-    AC_MSG_CHECKING([whether a simple qt program can be built without -fPIC])
+    AC_MSG_CHECKING([whether a simple Qt program can be built])
     AC_LINK_IFELSE([AC_LANG_SOURCE([
       #include <QCoreApplication>
       int main (int argc, char **argv) {
@@ -55,25 +54,6 @@ AC_DEFUN([FIND_QT6],
     AC_MSG_RESULT([$have_qt6_libs])
     AC_LANG_POP()
 
-    if test "$have_qt6_libs" = "no" -a "$have_w32_system" != yes; then
-      # try building with -fPIC
-      CPPFLAGS="$GPGME_QT6_CFLAGS -fPIC"
-      LIBS=$GPGME_QT6_LIBS
-      AC_LANG_PUSH(C++)
-      AC_MSG_CHECKING([whether a simple qt program can be built with -fPIC])
-      AC_LINK_IFELSE([AC_LANG_SOURCE([
-        #include <QCoreApplication>
-        int main (int argc, char **argv) {
-        QCoreApplication app(argc, argv);
-        app.exec();
-      }])], [
-        have_qt6_libs='yes'
-        GPGME_QT6_CFLAGS="$GPGME_QT6_CFLAGS -fPIC"
-      ], [have_qt6_libs='no'])
-      AC_MSG_RESULT([$have_qt6_libs])
-      AC_LANG_POP()
-    fi
-
     CPPFLAGS=$OLDCPPFLAGS
     LIBS=$OLDLIBS
   fi