proc: consoles: Add notation to c_start/c_stop

fs/proc/consoles.c:78:13: warning: context imbalance in 'c_start'
	- wrong count at exit
fs/proc/consoles.c:104:13: warning: context imbalance in 'c_stop'
	- unexpected unlock

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-13-john.ogness@linutronix.de


Signed-off-by: Petr Mladek <pmladek@suse.com>