lsm: fix typo in security_file_lock() comment header

In the description of function definition security_file_lock(),
the line "@cmd: fnctl command" has a typo where "fnctl" should be
"fcntl". This patch fixes the typo.
Signed-off-by: Pairman Guo <pairmanxlr@gmail.com>
[PM: commit message cleanup]
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/security.c

@@ -2717,7 +2717,7 @@ int security_file_lock(struct file *file, unsigned int cmd)
 /**
  * security_file_fcntl() - Check if fcntl() op is allowed
  * @file: file
- * @cmd: fnctl command
+ * @cmd: fcntl command
  * @arg: command argument
  *
  * Check permission before allowing the file operation specified by @cmd from