staging: dgap: tty.c: removes smatch warnings "redundant null check"

This patch removes these smatch warnings:
redundant null check on dgap_TmpWriteBuf calling kfree()
redundant null check on brd->SerialDriver->ttys calling kfree()
redundant null check on brd->PrintDriver->ttys calling kfree()

The code checked to see if these variables are null
before freeing. This check isn't needed.
Signed-off-by: Lidza Louina <lidza.louina@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgap/dgap_tty.c

@@ -497,10 +497,8 @@ int dgap_tty_init(struct board_t *brd)
  */
 void dgap_tty_post_uninit(void)
 {
-	if (dgap_TmpWriteBuf) {
 	kfree(dgap_TmpWriteBuf);
 	dgap_TmpWriteBuf = NULL;
-	}
 }
 
 
@@ -522,10 +520,8 @@ void dgap_tty_uninit(struct board_t *brd)
 			tty_unregister_device(brd->SerialDriver, i);
 		}
 		tty_unregister_driver(brd->SerialDriver);
-		if (brd->SerialDriver->ttys) {
 		kfree(brd->SerialDriver->ttys);
 		brd->SerialDriver->ttys = NULL;
-		}
 		put_tty_driver(brd->SerialDriver);
 		brd->dgap_Major_Serial_Registered = FALSE;
 	}
@@ -538,10 +534,8 @@ void dgap_tty_uninit(struct board_t *brd)
 			tty_unregister_device(brd->PrintDriver, i);
 		}
 		tty_unregister_driver(brd->PrintDriver);
-		if (brd->PrintDriver->ttys) {
 		kfree(brd->PrintDriver->ttys);
 		brd->PrintDriver->ttys = NULL;
-	        }
 		put_tty_driver(brd->PrintDriver);
 		brd->dgap_Major_TransparentPrint_Registered = FALSE;
 	}