kbuild: Fix checking of scm-identifier variable

I'm looking Makefile in the -mm branch (dated 2010-04-28-16-53) and
seeing what looks like a bug in the checking of scm-identifier.  The
"ifneq ($scm-identifier)" seems to always execute "ifeq
($(LOCALVERSION,)) ...".  This patch fixes the checking of
scm-identifier.
Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Makefile

@@ -943,7 +943,7 @@ endif
 ifdef CONFIG_LOCALVERSION_AUTO
 	localver-extra = $(scm-identifier)
 else
-	ifneq ($scm-identifier,)
+	ifneq ($(scm-identifier),)
 		ifeq ($(LOCALVERSION),)
 			localver-extra = +
 		endif