configure.ac: Fix trailing whitespace

Change-Id: I5abdce5daef43dad772bf52576b47c0867d65c98
diff --git a/configure.ac b/configure.ac
index 9432715..db2e1ad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -22,7 +22,7 @@
 AC_PROG_INSTALL
 LT_INIT
 
-dnl patching ${archive_cmds} to affect generation of file "libtool" to fix linking with clang 
+dnl patching ${archive_cmds} to affect generation of file "libtool" to fix linking with clang
 AS_CASE(["$LD"],[*clang*],
   [AS_CASE(["${host_os}"],
      [*linux*],[archive_cmds='$CC -shared $pic_flag $libobjs $deplibs $compiler_flags $wl-soname $wl$soname -o $lib'])])