matroxfb: fix regression with uninitalized fb_info->mm_lock mutex

Remove redundant call to the matroxfb_update_fix() before matrox
frambuffer is registered.

This fixes a problem with uninitialized the fb_info->mm_lock mutex
introduced by the commit 537a1bf0 " fbdev: add mutex for fb_mmap
locking"
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/matrox/matroxfb_base.c

@@ -1876,7 +1876,6 @@ static int initMatrox2(WPMINFO struct board* b){
 	}
 	matroxfb_init_fix(PMINFO2);
 	ACCESS_FBINFO(fbcon.screen_base) = vaddr_va(ACCESS_FBINFO(video.vbase));
-	matroxfb_update_fix(PMINFO2);
 	/* Normalize values (namely yres_virtual) */
 	matroxfb_check_var(&vesafb_defined, &ACCESS_FBINFO(fbcon));
 	/* And put it into "current" var. Do NOT program hardware yet, or we'll not take over