[gdm] Add -lm to greeter libs

[Ray Strode <halfline src gnome org>]

commit 1e01955ac5feb3a08d1b3b5d397a16d514f0ff0b
Author: Ray Strode <rstrode redhat com>
Date:   Wed Feb 17 13:33:20 2010 -0500

    Add -lm to greeter libs

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index e824331..aad1f06 100644
--- a/configure.ac
+++ b/configure.ac
@@ -122,6 +122,7 @@ PKG_CHECK_MODULES(SIMPLE_GREETER,
 	fontconfig >= $FONTCONFIG_REQUIRED_VERSION
 	x11
 )
+SIMPLE_GREETER_LIBS="$SIMPLE_GREETER_LIBS -lm"
 AC_SUBST(SIMPLE_GREETER_CFLAGS)
 AC_SUBST(SIMPLE_GREETER_LIBS)