console: rename acquire/release_console_sem() to console_lock/unlock()

The -rt patches change the console_semaphore to console_mutex.  As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()

This commit makes things use more neutral function names which dont make
implications about the underlying lock.

The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()

This patch also paves the way to switching console_sem from a semaphore to
a mutex.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c
index 3e6934d..a20218c 100644
--- a/drivers/video/xen-fbfront.c
+++ b/drivers/video/xen-fbfront.c
@@ -491,12 +491,12 @@
 	if (console_set_on_cmdline)
 		return;
 
-	acquire_console_sem();
+	console_lock();
 	for_each_console(c) {
 		if (!strcmp(c->name, "tty") && c->index == 0)
 			break;
 	}
-	release_console_sem();
+	console_unlock();
 	if (c) {
 		unregister_console(c);
 		c->flags |= CON_CONSDEV;