build: move library flags from EXTRA_LDFLAGS to LIBS

LIBS is the variable that Autoconf uses to put library flags.  From the
manual of GNU Autoconf (version 2.69):

>  -- Variable: LDFLAGS
>
>      [...]
>
>      This variable's contents should contain options like '-s' and '-L'
>      that affect only the behavior of the linker.  Please see the
>      explanation of 'CFLAGS' for what you can do if an option also
>      affects other phases of the compiler.
>
>      Don't use this variable to pass library names ('-l') to the linker;
>      use 'LIBS' instead.
>
>  -- Variable: LIBS
>
>      '-l' options to pass to the linker.  The default value is empty,
>      but some Autoconf macros may prepend extra libraries to this
>      variable if those libraries are found and provide necessary
>      functions, see *note Libraries::.  'configure' uses this variable
>      when linking programs to test for C, C++, Objective C, Objective
>      C++, Fortran, and Go features.

1 files changed, 4 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 416d79682..556019232 100644
--- a/configure.ac
+++ b/configure.ac
@@ -72,7 +72,7 @@ AS_IF([test "x$enable_apparmor" = "xyes"], [
         HAVE_APPARMOR="-DHAVE_APPARMOR"
         PKG_CHECK_MODULES([AA], [libapparmor], [
                 EXTRA_CFLAGS="$EXTRA_CFLAGS $AA_CFLAGS"
-                EXTRA_LDFLAGS="$EXTRA_LDFLAGS $AA_LIBS"
+                LIBS="$LIBS $AA_LIBS"
         ])
 ])
 
@@ -82,7 +82,7 @@ AC_ARG_ENABLE([selinux],
     [AS_HELP_STRING([--enable-selinux], [SELinux labeling support])])
 AS_IF([test "x$enable_selinux" = "xyes"], [
         HAVE_SELINUX="-DHAVE_SELINUX"
-        EXTRA_LDFLAGS="$EXTRA_LDFLAGS -lselinux"
+        LIBS="$LIBS -lselinux"
 ])
 
 AC_SUBST([EXTRA_CFLAGS])
@@ -226,7 +226,8 @@ AC_ARG_ENABLE([gcov],
     [AS_HELP_STRING([--enable-gcov], [Gcov instrumentation])])
 AS_IF([test "x$enable_gcov" = "xyes"], [
         HAVE_GCOV="--coverage -DHAVE_GCOV"
-        EXTRA_LDFLAGS="$EXTRA_LDFLAGS -lgcov --coverage"
+        EXTRA_LDFLAGS="$EXTRA_LDFLAGS --coverage"
+        LIBS="$LIBS -lgcov"
 ])
 
 HAVE_CONTRIB_INSTALL="yes"