fbdev: uninline lock_fb_info()

Before:

   text    data     bss     dec     hex filename
   3648    2910      32    6590    19be drivers/video/backlight/backlight.o
   3226    2812      32    6070    17b6 drivers/video/backlight/lcd.o
  30990   16688    8480   56158    db5e drivers/video/console/fbcon.o
  15488    8400      24   23912    5d68 drivers/video/fbmem.o

After:

   text    data     bss     dec     hex filename
   3537    2870      32    6439    1927 drivers/video/backlight/backlight.o
   3131    2772      32    5935    172f drivers/video/backlight/lcd.o
  30876   16648    8480   56004    dac4 drivers/video/console/fbcon.o
  15506    8400      24   23930    5d7a drivers/video/fbmem.o

Cc: Andrea Righi <righi.andrea@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fb.h b/include/linux/fb.h
index fe7d0d7..f563c50 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -961,15 +961,7 @@
 extern int num_registered_fb;
 extern struct class *fb_class;
 
-static inline int lock_fb_info(struct fb_info *info)
-{
-	mutex_lock(&info->lock);
-	if (!info->fbops) {
-		mutex_unlock(&info->lock);
-		return 0;
-	}
-	return 1;
-}
+extern int lock_fb_info(struct fb_info *info);
 
 static inline void unlock_fb_info(struct fb_info *info)
 {