Fix !ifdef in nmake.defs.

 nt/nmake.defs: Use !if, not !ifdef.  See
 http://lists.gnu.org/archive/html/help-emacs-windows/2012-11/msg00027.html
 for the details.

nt/ChangeLog

 2012-11-20  Eli Zaretskii  <eliz@gnu.org>
 
+	* nmake.defs: Use !if, not !ifdef.  See
+	http://lists.gnu.org/archive/html/help-emacs-windows/2012-11/msg00027.html
+	for the details.
+
 	* inc/stdint.h (INTPTR_MIN): Define for MSVC.
 
 2012-11-19  Eli Zaretskii  <eliz@gnu.org>

nt/nmake.defs

@@ -116,7 +116,7 @@ RC_INCLUDE	= -i
 
 USE_CRT_DLL	= 1
 
-!ifdef USE_CRT_DLL
+!if USE_CRT_DLL
 libc		= msvcrt$(D).lib
 EMACS_EXTRA_C_FLAGS= -D_DLL -D_MT -DUSE_CRT_DLL=1
 !else